US President Donald Trump said the United States was starting direct, high-level talks with Iran over its nuclear programme on Saturday, in an announcement during a White House meeting with Israeli Prime Minister Benjamin Netanyahu.

Speaking on Monday in the Oval Office, Trump said he was hopeful of reaching a deal with Tehran, but warned that the Islamic republic would be in "great danger" if the talks failed.

Hours later Tehran confirmed discussions were set for Saturday in Oman, but stressed they were "indirect" talks.

"Iran and the United States will meet in Oman on Saturday for indirect high-level talks," Iranian Foreign Minister Abbas Araghchi said on social media platform X.

"It is as much an opportunity as it is a test," he added.

"The ball is in America's court."

Netanyahu meanwhile said the United States and Israel were working on another deal to free hostages from war-torn Gaza, where a ceasefire between Israel and Iran's ally Hamas has collapsed.

"We're dealing with the Iranians, we have a very big meeting on Saturday and we're dealing with them directly," Trump told reporters after a meeting that was meant to focus on Israel's bid to avoid US tariffs.

Trump did not say where the talks would take place, but insisted they would not involve surrogates and would be at "almost the highest level."

Trump's stunning announcement came a day after Iran dismissed direct negotiations on a new deal to curb the country's nuclear programme, calling the idea pointless.

The US president pulled out of the last deal in 2018, during his first presidency, and there has been widespread speculation that Israel, possibly with US help, might attack Iranian facilities if no new agreement is reached.

Trump issued a stern warning to Tehran, however.

"I think if the talks aren't successful with Iran, I think Iran's going to be in great danger, and I hate to say it, great danger, because they can't have a nuclear weapon," he said. (AFP)