WASHINGTON - US President Donald Trump said Thursday that Iran has 10 to 15 days to reach a deal over its nuclear program, otherwise "really bad things" will happen.

"I would think that would be enough time," he told reporters aboard Air Force One.

"We're either going to get a deal or it's going to be unfortunate for them," Trump said.

Earlier on Thursday, Trump said at the inaugural meeting of the "Board of Peace" that the outcome of the US-Iran nuclear talks will be decided over the next 10 days, calling Iran "a hot spot right now."

"It's proven to be, over the years, not easy to make a meaningful deal with Iran, and we have to make a meaningful deal. Otherwise bad things happen," Trump said.

US Vice President JD Vance said that the second round of the US-Iran talks in Geneva on Tuesday showed "some" positive signs but key US red lines remain unmet.

A Trump adviser estimated a "90 percent chance" of strikes within weeks if talks fail, Axios reported Tuesday.

The aircraft carrier USS Gerald R. Ford was approaching Gibraltar on Wednesday as it made its way from the Caribbean to join the aircraft carrier USS Abraham Lincoln in waters near Iran, according to local media reports.