In announcing his pullout from a deal that failed to "put America first," the US president on Thursday cited the northeastern city saying: "I was elected to represent the citizens of Pittsburgh, not Paris".
But Peduto took issue with Trump's invocation of his city.
"As the Mayor of Pittsburgh, I can assure you that we will follow the guidelines of the Paris Agreement for our people, our economy & future," he posted in one of a feisty series of tweets that swiftly went viral.
The president's decision to quit the 196-party accord sparked indignation at home and abroad, with former president Barack Obama saying the United States was "joining a handful of nations that reject the future".
Peduto echoed that criticism, tweeting: "The United States joins Syria, Nicaragua & Russia in deciding not to participate with world's Paris Agreement. It's now up to cities to lead."
Trump went on to declare: "It is time to put Youngstown, Ohio; Detroit, Michigan; and Pittsburgh, Pennsylvania - along with many other great locations in our country - before Paris, France."
But Pittsburgh is hardly a depressed post-industrial hub in need of a savior - it has experienced a striking rebirth in recent years.
Peduto stressed that Pittsburgh was far removed from the Rust Belt cities that helped propel the Republican businessman to the White House.
"Fact: Hillary Clinton received 80% of the vote in Pittsburgh. Pittsburgh stands with the world & will follow Paris Agreement," he tweeted.
