Iran is preparing a counter-proposal after rejecting the U.S. nuclear deal, prompting President Trump to caution that "time is running out."

Trump said after a phone call with Putin on Wednesday that time was running out for Iran to make a decision on its nuclear programme and that he believed Putin agreed that the Islamic Republic should not have nuclear weapons.

Iran’s supreme leader, Ayatollah Ali Khamenei, said on Wednesday that abandoning uranium enrichment was “100 percent” against Tehran’s interests, effectively rejecting a key U.S. demand in weeks of tense negotiations over Iran’s nuclear program.