US President Donald Trump said on Friday there had been some "pretty good news" regarding Iran, adding that the US and Iran's temporary ceasefire may end unless a long-term deal to end the war is agreed upon by Wednesday.

"We had some pretty good news 20 minutes ago, but it seems to be going very well in the Middle East with Iran," Trump told reporters aboard Air Force One on his way back to Washington from Phoenix, Arizona.

"You'll hear about. I just think it should happen. It's something that only makes sense to happen. And I think it will. We'll see what happens, but I think it will," Trump said when asked what the good news was.

He also stated that the US and Israel would resume their attacks on Iran in case negotiations failed, while insisting that the blockade of the Strait of Hormuz would remain until a deal was reached with Iran.

"Maybe I won't extend it, but the blockade (on Iranian ports) is going to remain," Trump told reporters. "So you have a blockade, and unfortunately, we have to start dropping bombs again."

CNN: Negotiations to continue on Monday

According to a CNN report, the negotiations between Iran and the US are due to continue on Monday, with no venue decided yet.

The report noted that neither the US nor Iran confirmed this news, while only Trump referred to the talks having "good progress."

Some of Trump's latest statements, such as Iran agreeing to the US taking possession of their enriched uranium, were already denied by Iranian officials, with no clear sign of the real progress of negotiations.

Iranian officials also denied Trump's claim that the Strait of Hormuz was open to "all ships," saying that vessels needed to coordinate the crossing with Iran and the Islamic Revolutionary Guard Corps through a secure waterway.