Iran's Supreme leader has criticised "bullying" countries in an apparent response to Donald Trump's comments that he had sent a letter to Iran demanding negotiations on its nuclear programme. Trump said on Friday he had warned Tehran in a letter it could face military action unless it agreed to talks for a nuclear deal.

President Trump said he sent a letter to Iran's Supreme Leader Ayatollah Ali Khamenei last week asking that the two leaders "negotiate" over the Islamic republic's nuclear program. On Saturday, the Iranian leader condemned the effort by unnamed "bullying governments" to make a deal over the program.

President Donald Trump says he sent a letter to Iran’s Ayatollah Ali Khamenei, a development that was not immediately confirmed by the supreme leader.

Trump revealed this week that he was seeking to strike a new deal with the Iranian regime, after withdrawing from an Obama-era agreement in his first term.

The letter appears to be President Trump’s opening bid to see if a newly vulnerable Iran is willing to negotiate.

Iran has not yet received a letter from the U.S. proposing negotiations regarding its nuclear program, as reported by Iran's representation at the UN. Previously, the Iranian news agency associated with the Supreme National Security Council expressed skepticism about President Donald Trump’s proposal.