Russia is recruiting Syrians and other foreign fighters as it ramps up its assault on Ukraine, the Pentagon has said.
Russia entered the Syrian civil war in 2015 on the side of President Bashar al-Assad's regime. Syria has been mired in a conflict marked by urban combat for more than a decade.
Now, United States Department of Defence officials said, Russia's President Vladimir Putin was "on a recruiting mission" seeking to bring some of those fighters into the fray in Ukraine.
According to the Wall Street Journal, US officials said that Russia — which launched an invasion into its Eastern European neighbour on 24 February — has in recent days recruited fighters from Syria hoping they can help take the capital Kyiv.
One official told the newspaper that some fighters are already in Russia readying to join the fight in Ukraine, though it was not immediately clear how many combatants have been recruited.
Details were slight: officials would not speculate on how many mercenaries have joined the fight, or on the quality of the fighters. But the Pentagon said there was no reason to doubt the accuracy of the reports.
"We do believe that the accounts of them — the Russians— seeking Syrian fighters to augment their forces in Ukraine, we believe there's truth to that," Pentagon spokesman John Kirby told journalists when asked about the reports.
But with enormous firepower and more than 150,000 deployed troops at Mr Putin's disposal, the Pentagon said it was noteworthy that he would find it necessary to recruit mercenaries.
"It's interesting that Mr Putin would have to find himself relying on foreign fighters here," Mr Kirby said, though he acknowledged the Pentagon does not have "perfect visibility" on exactly who was joining the cause.
Earlier on Monday (local time), a senior defence official told reporters more directly: "We know that they're trying to recruit Syrians for the fight."
Foreign combatants have already entered the Ukrainian conflict on both sides.
Residents of Irpin flee heavy fighting via a destroyed bridge as Russian forces entered the city on 7 March, 2022 in Irpin, Ukraine. Source: Getty / Chris McGrath
'Almost all' Russian border troops activated
Meanwhile, the US will send 500 more troops to Europe to boost NATO security, while the Pentagon determined Russia has committed nearly all its combat power stationed along the border into Ukraine.
With Mr Putin intensifying operations, a senior US defence official also warned on Monday that Russian strikes on civilians were mounting.
The US has already deployed 12,000 additional soldiers to Europe this year, but President Joe Biden has stressed that US troops will not engage in a conflict with Russian forces in Ukraine.
Over the weekend, Secretary of Defence Lloyd Austin ordered an extra "500 US military personnel to locations in Europe to augment existing forces," the defence official told reporters.
"These additional forces are going to be positioned to respond to the current security environment in light of Russia's renewed aggression against Ukraine, and to reinforce deterrence and defensive capabilities of NATO."
The Defence Department has assessed that of the Russian forces built up along the border — estimated by Western nations at over 150,000 troops — Mr Putin "has committed nearly 100 per cent of his combat power into Ukraine," the official said.
"He's got almost all of them in."
People rush to an evacuation train at the central train station in Odesa, Ukraine, on 7 March, 2022. Source: AFP, Getty / Bulent Kilic
Bombardments have increased around the capital Kyiv, Kharkiv, Chernihiv in the north, and Mykolaiv and Mariupol in the south, and "we do assess that these strikes are hitting civilian targets, civil infrastructure, residential areas," he said.
It remained unclear whether the strikes on civilians were deliberate, but the official stressed that "it's happening at a greater rate and on a greater scale, and (is) all the more evidence of the reckless nature with which the Russians are propagating this invasion."
In a televised address marking International Women's Day, Mr Putin said he will not send conscripts or reservists to fight in Ukraine and that "professional" soldiers fulfilling "fixed objectives" were leading the war.
"Conscripted soldiers are not participating and will not participate in the fighting. There will not be an additional conscription of reservists either," Mr Putin said.
"The fixed objectives are only carried out by professional servicemen. I am sure they are guaranteeing security and peace for the Russian people in an effective manner," Mr Putin added.
Meanwhile, concern has grown that Odesa, the country's main port, is in Russia's sights.
Ukrainian President Volodymyr Zelenskyy warned on Sunday that Russia was "preparing to bomb Odesa".
But the defence official said the Pentagon has "not seen any evidence of a movement on Odesa" yet.
"We believe the Russians want to take Odesa," and the Pentagon was not ruling out the potential for a Russian amphibious assault supported by ground troops, he said.
Ukraine hits out at Russia over humanitarian corridors
Ukrainian President Volodymyr Zelenskyy on Monday (local time) accused the Russian army of scuppering the evacuation of civilians through humanitarian corridors agreed after talks with Moscow.
"There was an agreement on humanitarian corridors. Did that work? Russian tanks worked in its place, Russian Grads (multiple rocket launchers), Russian mines," he said in a video posted on Telegram.
The Ukrainian leader said Russian forces mined the road chosen to bring food and medicine to the besieged city of Mariupol in southern Ukraine.
Accusing Russia of "cynicism", Mr Zelenskyy also said Russian troops destroyed buses that were due to evacuate civilians from the combat zones.
"They ensure that a small corridor to the occupied territory is open for a few dozen people. Not so much towards Russia as towards the propagandists, directly towards the television cameras," he said.
But Mr Zelenskyy added that Kyiv would continue to negotiate with Russia to reach a peace deal.
"I'm staying here, I'm staying in Kyiv ... I'm not afraid," he said.
Ukrainian President Volodymyr Zelenskyy. Source: Getty / Laurent Van Der Stockt/Getty Images
But Ukraine refused to evacuate civilians to Russia as four of Moscow's six proposed corridors led to Russia or its ally Belarus.
Russia on Monday evening announced that local ceasefires in Ukrainian cities including the capital Kyiv, Kharkiv, Mariupol and Sumy would begin from 0700 GMT (6pm AEDT) on Tuesday to facilitate the evacuation of civilians.
Russia has said the routes are still due to be approved by Ukraine.
Bloodshed continues
It comes after the latest round of talks between delegations from Russia and Ukraine.
Kyiv said there had been "positive results" from the third round of negotiations on Monday, focused on giving civilians evacuation routes from besieged towns, but Russia said its expectations from the talks were "not fulfilled".
The bloodshed continued on day 12 of the war, with 13 people killed in shelling on an industrial bakery in the town of Makariv and the mayor of the town of Gostomel killed while delivering bread to civilians.
The invasion ordered by Mr Putin has pushed more than 1.7 million people across Ukraine's borders in what the UN calls Europe's fastest-growing refugee crisis since World War Two.
International sanctions intended to punish Russia have done little to slow the invasion, and energy-hungry Western nations are still weighing up whether to ban Russian oil imports.
The conflict pushed oil prices to a near 14-year high, while gas prices also rocketed and stock markets around the world plunged over concerns about the effect on the global economy.
Ukraine had earlier rejected a Russian proposal for humanitarian corridors from the cities of Kharkiv, Kyiv, Mariupol and Sumy, as many of the routes led straight into Russia or its ally Belarus.
"This is not an acceptable option," Ukrainian Deputy Prime Minister Iryna Vereshchuk said.
French President Emmanuel Macron, who spoke to Mr Putin on Sunday, accused Mr Putin of "moral and political cynicism" over the offer.
'So happy to get out'
Outgunned Ukrainian forces have been trying to hold back Russian forces besieging cities as they push up from the east and south up in an attempt to encircle the capital Kyiv.
Twelve days of fighting have left hundreds dead.
Journalists from news agency AFP witnessed thousands of civilians on Monday fleeing the fighting via an unofficial humanitarian corridor in Irpin, a strategic suburb west of Kyiv.
A day earlier eight people died there in shelling, Ukrainian officials said. Images of the killing of a family of four shocked the world on Sunday.
"I am so happy to have managed to get out," said Olga, a 48-year-old woman leaving with her two dogs.
Children and the elderly were carried on carpets used as stretchers on the route, which leads over a makeshift bridge and then a single path secured by the army and volunteers.
A Ukrainian military member stands guard next to a damaged church as people flee from the frontline town of Irpin, Ukraine, on 7 March 2022. Source: EPA, AAP / Roman Pilipey
"We had no light at home, no water, we just sat in the basement," Inna Scherbanyova, 54, an economist from Irpin, told AFP.
"Explosions were constantly going off ... Near our house there are cars, there were dead people in one of them ... very scary."
Two recent attempts to allow some 200,000 civilians to leave the besieged Azov Sea port of Mariupol have also ended in disaster.
Refugees trying to escape Mariupol using humanitarian corridors were left stranded as the road they were directed towards was mined, the ICRC said on Monday.
The talks that took place in Belarus later "achieved some positive results concerning the logistics of humanitarian corridors," Kyiv's presidential advisor Mikhailo Podolyak tweeted.
But Russia's lead negotiator Vladimir Medinsky said in televised remarks that "our expectations from negotiations were not fulfilled. We hope that next time we will be able to take a more significant step forward".
Secure the skies
Mr Zelenskyy has also renewed calls for the West to boycott Russian exports, particularly oil, and to impose a no-fly zone to stop the carnage.
"How many more deaths and losses must it take to secure the skies over Ukraine?" he said in a video message.
Western allies have imposed unprecedented sanctions against businesses, banks and billionaires in a bid to choke the Russian economy and pressure Mr Putin to halt his assault.
Russia has been forced to restrict sales of essential goods to limit black market speculation, while a stream of foreign companies have halted business in the country.
Iconic US jeans brand Levi's became the latest to join the exodus, but Japanese casualwear giant Uniqlo defended its decision to stay, saying: "Clothing is a necessity of life."
Calls to choke off Russia's war chest by embargoing oil imports however remain problematic for Western countries, despite the US saying it was in talks with Europe to ban them.
The leaders of Germany, Britain and the Netherlands warned on Monday against such a ban, however, saying it could put Europe's energy security at risk
NATO countries have pumped weapons into Ukraine but have so far rebuffed Ukraine's calls for a no-fly zone, with one prominent US senator, Marco Rubio, saying on Sunday that it could lead to "World War Three" against nuclear-armed Russia.
Mr Putin has equated global sanctions with a declaration of war, put nuclear forces on alert and warned that Kyiv is "putting in question the future of Ukrainian statehood" by continuing to resist.
A building in Vasylkiv, not far from Kyiv, was destroyed during an attack by Russian forces on the town. Source: EPA, AAP / Mikhail Palinchak
Despite harsh punishments for those voicing dissent, protests in Russia against the Ukraine invasion have continued, with more than 10,000 people arrested since it began.
Protests have also taken place across Europe. The Russian embassy in Dublin on Monday condemned the ramming of its gates by a truck on Monday.
The invasion has triggered a wave of refugees -- mainly women and children -- into eastern European countries, with Poland taking much the burden.
EU foreign policy chief Josep Borrell said Europe could see the entry of five million Ukrainian refugees "if the indiscriminate bombardments of cities continues."
Sputtering diplomatic efforts to resolve the conflict continue with the foreign ministers of Ukraine, Russia and Turkey set to meet in southern Turkey on Thursday, Ankara said.
China said on Monday it was open to helping to mediate peace but stressed that the friendship with its close ally Russia remained "rock solid".
The International Court of Justice meanwhile heard Ukraine's appeal for it to order Russia to halt the fighting, but Russia declined to attend the sitting of the UN's top court, in The Hague.
