US Ambassador to NATO Matt Whitaker said Tuesday that President Donald Trump personally controls all decisions regarding Iran while remaining willing to pursue a peaceful resolution through diplomacy.

"President Trump ... holds all the decisions, but he's willing to give real diplomacy a chance to solve this peacefully," Whitaker told Fox News as indirect nuclear talks concluded in Geneva, Switzerland, on Tuesday.

The ambassador emphasized Washington's firm stance, saying Trump "has been very clear that the number one state sponsor of terror can't have nuclear weapons or the capacity to build them."

Whitaker noted that the US president "obliterated their program once with Operation Midnight Hammer," referring to June 2025 strikes that targeted three key Iranian nuclear facilities – Fordow, Natanz, and Isfahan.

He added that the threat of further military action looms with an American armada positioned close to the region.

Washington significantly steps up its military presence in the region, deploying the USS Abraham Lincoln carrier strike group with plans to send the USS Gerald R. Ford aircraft carrier as well.

If diplomacy "doesn't work out, as he (Trump) said, 'It will be a very bad day for Iran,'" the ambassador warned.

The second round of indirect nuclear negotiations between Iran and the US concluded in Geneva on Tuesday, with both sides exchanging notes on nuclear, legal, and economic matters through Omani mediators.

Both delegations met separately with Omani Foreign Minister Badr Albusaidi at the Omani Embassy before communicating through intermediaries.

The two countries reached a general agreement on a set of "guiding principles" to serve as the basis for beginning work on a text of a potential deal, Iranian Foreign Minister Abbas Araghchi noted on Tuesday after the talks concluded.

The first round of talks took place in Muscat earlier this month, more than eight months after diplomacy was suspended following the Iran-Israel war last June.