Iran's leadership warned of a regional conflict on Sunday if the U.S. were to attack it, and designated EU armies as "terrorist groups" in a retaliatory move.

The Iranian leader who slammed President Donald Trump just days ago said Tuesday that his country is now pursing "fair and equitable negotiations."

Washington and Tehran are set to hold nuclear talks in Oman this Friday as U.S. military pressure mounts and Iran insists on red lines over its missile programme.

Trump-Iran latest: US military shoots down Iranian drone as Tehran demands venue change for talks - The incident came ahead of planned talks between Iran and the United States

Trump been ratcheting up threats against Iran over the past several weeks, urging a nuclear deal and increasing U.S military presence in the region.

Iran’s so-called axis of resistance, its regional network of armed proxies and allied militant groups, could come to the fray to provide additional firepower to Tehran in the event of a conflict with the United States,

Even with US forces poised to strike Iran, Foreign Minister Abbas Araghchi told CNN that he was “confident that we can achieve a deal” on Tehran’s nuclear program.

Tensions have continued to rise between the two nations after the Iranian regime’s brutal crackdown on nationwide protests left thousands dead.