TEHRAN -- Iranian President Masoud Pezeshkian said on Saturday the United States is the main obstacle to reviving the 2015 nuclear deal, as UN sanctions lifted under the pact were set to be reimposed later in the day.

Speaking at Tehran airport after returning from the UN General Assembly in New York, Pezeshkian said France, Britain, and Germany — who triggered the "snapback" mechanism — had been told of Iran's readiness to cooperate with the International Atomic Energy Agency during his visit to the UN.

"The United States always attempts to prevent the achievement of an agreement by raising fresh pretexts," he said. "The reality is that the United States cannot tolerate a strong Iran and wants to weaken our country."

Last month, the three European powers invoked the snapback clause of the Joint Comprehensive Plan of Action (JCPOA), restoring UN sanctions that had been lifted in exchange for limits on Tehran's nuclear program.

Ahead of the measures taking effect, Iran recalled its ambassadors to the three capitals. Foreign Minister Abbas Araghchi said on Saturday the snapback was "illegal, void, and has no standing," blaming the crisis on "US betrayal and Europe's inaction."

"The US betrayed diplomacy. The Europeans buried it," he said.

The JCPOA, signed in 2015 between Iran and six world powers, has been under strain since Washington withdrew in 2018, prompting Tehran to gradually scale back compliance.