Iranian President Hassan Rouhani said that President-elect Donald Trump’s promise to dismantle the nuclear deal between Iran and world powers is “empty talk,” and that Trump cannot unilaterally end the international agreement. 

"The president-elect has shown he is not happy about the nuclear deal, calling it the worst deal ever signed. This is only empty talk," Rouhani said at a news conference on the one-year anniversary of the lifting of international sanctions against Iran, Reuters reported. 

"I don't think he can do much when he goes to the White House," said Rouhani. The Iranian leader said he is "optimistic about the future of the nuclear deal," adding that the accord is "good for the United States, but he (Trump) doesn't understand." 

During the 2016 presidential campaign, Trump called the Iran agreement “the worst deal ever negotiated” and promised to “rip up” the pact, which was signed by the U.S., the U.K., France, Germany, Russia, China and Iran in July 2015. 

But Trump has backtracked slightly since winning the presidential election, saying more recently that he would “police that contract so tough that they (the Iranians) don't have a chance.” Trump’s pick for secretary of state, Rex Tillerson, has said he would recommend a “full review” of the nuclear deal, but stopped short of saying he would dismantle it.