Trump warns of ‘bad, bad things’ for Iran if nuclear deal not reached

US president Donald Trump warned Iran on Friday that “bad, bad things” would happen if Tehran did not agree to a nuclear deal, a day after Iran declined to have direct talks under his stepped-up sanctions.

“My big preference ... is we work it out with Iran. But if we don't work it out, bad, bad things are going to happen to Iran,” Trump told reporters in the Oval Office.

This is what Trump said he conveyed in his letter to Iran's supreme leader Ali Khamenei last week.

Tehran confirmed on Wednesday that a response to the letter had been sent via Oman.

"Our policy remains not to engage in direct negotiations under maximum pressure and military threats. However, indirect negotiations as existed in the past can continue," foreign minister Abbas Araghchi said.

Iran denies seeking a nuclear weapon but the UN's nuclear watchdog says it has enriched more uranium than any state lacking a bomb. While Washington assesses Tehran is not actively building one, it doubts Iranian intentions.

Trump last month reinstated the "maximum pressure" campaign of sanctions on Iran from his first term, with the stated aim of driving its oil sales to zero.

Trump's remarks come as Iran’s parliament speaker on Friday accused the US of using nuclear talks to pressure Tehran into relinquishing its defense capabilities.

“The US means disarmament when it says negotiation,” Mohammad Bagher Ghalibaf said in a speech during Quds Day rallies in Tehran on Friday. “Our people understand that talks under threat are just a show to impose their will. No wise nation would accept that.”

His comments were echoed by other senior Iranian officials speaking at Quds Day events showcasing Tehran's solidarity with Palestinians, including Foreign Minister Abbas Araghchi and senior adviser to Iran's Supreme Leader Ali Larijani.