Donald Trump suggests decision on Iran likely within 10 to 15 days

US President Donald Trump has said 10 to 15 days "pretty much the maximum" he would give Iran to make a deal over its nuclear program.

"We're either going to get a deal, or it's going to be unfortunate for them," he told journalists on an Air Force One flight on Thursday.

Earlier in the day in Washington, Trump had given Iran a similar timeframe.

"Maybe we're going to make a deal [with Iran]. You are going to be finding out over the next, probably, 10 days," he said during his speech at the first meeting of his controversial Board of Peace.