Tehran [Iran], November 1 (ANI): Iran's top security official, Mohsen Rezaei, has said that the United States has 'completely shifted tone' in a letter from Vice President JD Vance, Al Jazeera reported.

The statement marks the first on-the-record Iranian reaction to the diplomatic overture, even as US President Donald Trump continues to maintain that Tehran is seeking negotiations.

"Their tone has shifted completely, which is a good sign that shows that our people have secured their victory," Rezaei told state broadcaster IRIB.

Vance's letter was delivered to Rezaei, secretary of Iran's Supreme National Security Council, through Qatari mediators on Sunday. According to The New York Times, the proposal envisages direct talks under Vance's leadership, with Iran's nuclear programme forming part of the discussions from the beginning.

Meanwhile, The Wall Street Journal, citing a source, reported that the communication outlined a 'framework for negotiations' rather than specific peace terms. The report added that the letter was dispatched at Trump's direction.

Earlier, Foreign Minister Abbas Araghchi told Al Jazeera on Saturday that Tehran had studied the letter and described Washington's attempt to open dialogue as a 'positive step'. He further disclosed that an aide had travelled to Doha for consultations with mediators.

Citing sources, Al Jazeera reported that a meeting could be held within a week, with Doha or Istanbul being considered as possible venues.

Meanwhile, Iranian Supreme Leader Mojtaba Khamenei has cautioned that Iran's military would respond to any missteps by the US or Israel with a response that is "geographically unrestricted".

"If the enemies once again launch military or terrorist attacks, it is the armed forces of the Islamic Republic and the Iranian nation that will determine the time and conditions for their end," Khamenei said.

Speaking at the White House on Friday, Trump asserted that Tehran was keen to engage in negotiations.

'There are talks, they want to talk, they keep talking,' he said, adding, 'We have time, frankly.'

Trump further claimed that Iran was 'in a lot of trouble' and predicted that the conflict would end "very soon". (ANI)