US President Donald Trump has given Iran a two-month deadline to reach a new nuclear deal while simultaneously warning Tehran to immediately cease its support for Houthi rebels in Yemen, according to US officials and sources briefed on diplomatic communications.

In a letter delivered to Iran's Supreme Leader Ali Khamenei via Emirati intermediaries on March 7, Trump proposed direct negotiations on a new nuclear agreement but warned of consequences if Iran rejects the offer and continues advancing its nuclear programme, Axios reported on March 19.

"We can't let them have a nuclear weapon. Something is going to happen very soon. I would rather have a peace deal than the other option but the other option will solve the problem," Trump said in recent public remarks.

The letter was described as "tough" by sources familiar with its contents and was delivered by Trump envoy Steve Witkoff to UAE President Mohammed Bin Zayed, whose representative Anwar Gargash subsequently conveyed it to Iranian Foreign Minister Abbas Araghchi.

Several US allies, including Israel, Saudi Arabia and the UAE, were briefed on the letter's contents before its delivery to Iran, according to a US official.

Separately, Trump escalated pressure on Iran via his Truth Social platform regarding its support for Houthi rebels, writing on his social media platform that despite reports of reduced military assistance, "Iran must stop the sending of these Supplies IMMEDIATELY."

"Let the Houthis fight it out themselves," Trump stated, suggesting that without Iranian backing, the Yemeni group would be defeated quickly. "Tremendous damage has been inflicted upon the Houthi barbarians, and watch how it will get progressively worse — it's not even a fair fight, and never will be. They will be completely annihilated!"

The dual pressure campaign comes as Iran's nuclear programme has advanced significantly. According to the International Atomic Energy Agency (IAEA), Iran's stockpile of 60% enriched uranium is sufficient for six nuclear bombs if further enriched to 90%, though Iran denies pursuing nuclear weapons.

Khamenei initially dismissed Trump's letter as "a deception" designed to make Iran appear unwilling to negotiate. However, Iran's UN mission later issued a statement that did not rule out discussions about "potential militarisation" of its nuclear programme, while rejecting talks aimed at dismantling its "peaceful nuclear programme."

National Security Adviser Mike Waltz indicated that Iran must "hand over and give up" all elements of its nuclear programme including missiles, weaponisation and uranium enrichment, or "face a whole series of other consequences."

Iran's foreign ministry stated that Trump's letter is still being studied and a response is being drafted.