Iranian President Hassan Rouhani says the US will regret a decision to leave Iran's 2015 nuclear deal with world powers and Tehran will fiercely resist US pressure to limit its influence in the Middle East.
US President Donald Trump, a long-time critic of the deal reached between Iran and six powers in 2015 before he took office, has threatened to pull out unless European signatories of the accord fix what he calls its "flaws" by May 12.
"If they want to make sure that we are not after a nuclear bomb, we have said repeatedly that we are not and we will not be ... but if they want to weaken Iran and limit its influence whether in the region or globally, Iran will fiercely resist," Rouhani said in a speech broadcast live on state television on Monday.
Under the deal with the United States, France, Germany, Britain, Russia and China, Tehran restricted its uranium enrichment program to satisfy the powers that it could not be used to develop atomic bombs.
In exchange, Iran received relief from sanctions, most of which were lifted in January 2016.
Foreign Minister Mohammad Javad Zarif warned that Tehran's "fierce reaction to a violation of the nuclear deal with major powers will not be pleasant for America", state TV reported.
Britain, France and Germany remain committed to the nuclear accord but, in an effort to keep Washington in it, want to open talks on Iran's ballistic missile program, its nuclear activities beyond 2025 - when key provisions of the deal expire - and its role in the wars in Syria and Yemen.
