According to Tehran, "indirect" Iran-US nuclear talks mediated by Oman will be held on Tuesday, although Washington has previously pushed for other topics to be discussed including Iran's ballistic missiles and support for regional proxies.

The war games in the Strait of Hormuz, the duration of which was not specified, aim to prepare the Guards for "potential security and military threats" in the strait, state TV said.

Iranian politicians have repeatedly threatened to block the strait, a strategic waterway through which about 20 percent of global oil passes, as both sides ramp up pressure with talks continuing.

Tehran and Washington restarted negotiations this month after previous talks collapsed when Israel launched an unprecedented bombing campaign against Iran last June.

US Secretary of State Marco Rubio told reporters on Monday "we're hopeful there's a deal".

"The president always prefers peaceful outcomes and negotiated outcomes to things."

Considerable uncertainty surrounds the fate of Iran's stockpile of more than 400 kilogrammes of 60-percent enriched uranium that was last seen by nuclear watchdog inspectors in June.

"The foreign minister has arrived in Geneva at the head of a diplomatic and expert delegation to take part in the second round of nuclear negotiation," Iran's state-run IRIB wrote on its Telegram channel.

The top diplomat, Abbas Araghchi, wrote on X that he was meeting in Geneva with the head of the International Atomic Energy Agency, Rafael Grossi, "for deep technical discussion".

Grossi later confirmed the meeting on X, calling the conversation with Araghchi "in-depth" ahead of Tuesday's "important negotiations".

- Protest crackdown -

Araghchi is also set to hold talks with his Swiss and Omani counterparts as well as other international officials, Iran's foreign ministry said.

"I am in Geneva with real ideas to achieve a fair and equitable deal. What is not on the table: submission before threats," Araghchi added on X.

Washington has dispatched Middle East envoy Steve Witkoff and President Donald Trump's son-in-law Jared Kushner, the White House confirmed on Sunday.

The latest talks follow repeated threats from Trump of military action against Tehran, first over Iran's deadly crackdown on anti-government protests, and then more recently over the country's nuclear programme.

The West fears the programme is aimed at making a bomb, which Tehran denies.

On Friday, Trump said a change of government in Iran would be the "best thing that could happen", as he sent a second aircraft carrier to the Middle East to ratchet up military pressure.

His remarks came as demonstrations outside Iran against its clerical authorities swept a number of cities including in the US over the weekend.

Iranians inside the country have also defied the deadly crackdown on protests last month and have continued to shout slogans against the authorities out of their windows.

- 'Viable' deal -

Iran's deputy foreign minister told the BBC that Tehran would consider compromises on its uranium stockpile if Washington lifts sanctions that have crippled the country's economy.

"If we see the sincerity on their (American) part, I am sure we will be on a road to have an agreement," said Majid Takht-Ravanchi.

Israeli Prime Minister Benjamin Netanyahu said on Sunday that any deal must involve the removal of all enriched uranium from Iran as well as Tehran's ability to enrich more.

On February 6, Araghchi led the Iranian delegation in indirect talks with Witkoff and Kushner in Muscat.

Switzerland has played a key role in Tehran-Washington diplomacy, representing US interests in Iran since Washington broke off relations after the 1980 hostage crisis, a year after the Iranian revolution.

Iranian deputy foreign minister for economic diplomacy Hamid Ghanbari said Tehran was seeking a deal with the United States that would generate economic benefits for both countries, particularly in sectors such as aviation, mining and oil and gas, the Fars news agency reported.

"For the agreement to be viable, it is essential that the United States also be able to benefit from it in areas with strong and rapid economic return potential," he was quoted as saying.