Iran's top security official on Saturday said progress had been made towards negotiations with the United States, even as the Islamic republic's army chief warned Washington against launching military strikes.

US President Donald Trump confirmed the two sides were talking, while keeping the threat of an attack in the foreground.

Washington has deployed warships led by the USS Abraham Lincoln aircraft carrier off Iran's shores, after Trump threatened to intervene in the wake of Tehran's deadly crackdown on anti-government protests.

"Contrary to the hype of the contrived media war, structural arrangements for negotiations are progressing," said Ali Larijani, head of Iran's Supreme National Security Council.

He was speaking a day after the Kremlin said he held talks in Moscow with Russian President Vladimir Putin.

Iranian President Masoud Pezeshkian said on Saturday a broader conflict would hurt both Iran and the United States.

"The Islamic Republic of Iran has never sought, and in no way seeks, war and it is firmly convinced that a war would be in the interest of neither Iran, nor the United States, nor the region," he said in a call with Egyptian counterpart Abdel Fattah al-Sisi, according to the Iranian presidency.

Later Saturday, Trump confirmed that there was a dialogue between Washington and Tehran.

"(Iran is) talking to us, and we'll see if we can do something, otherwise we'll see what happens... we have a big fleet heading out there," he told Fox News.

"They are negotiating," he added.

Qatar's foreign ministry said its premier Sheikh Mohammed bin Abdulrahman Al Thani, who also serves as foreign minister, held talks in Tehran with Larijani on Saturday to try to "de-escalate tensions in the region".

The arrival of the US flotilla has raised fears of a direct confrontation with Iran, which has warned it would respond with missile strikes on US bases, ships and allies — notably Israel — in the event of an attack.

Trump has said he believes Iran will make a deal over its nuclear and missile programmes rather than face US military action.

Tehran has said it is ready for nuclear talks if its missiles and defence capabilities are not on the agenda. (AFP)