Iran is not currently planning to attend talks with the United States, state media said, after President Donald Trump ordered US negotiators to travel to Pakistan on Monday, just days before a ceasefire in the Middle East expires.

The ongoing US blockade of Iranian ports has been a significant sticking point, an issue further complicated by an American destroyer on Sunday firing on and seizing an Iranian ship that tried to evade it. Tehran warned it would retaliate.

State broadcaster IRIB on Sunday cited Iranian sources as saying "there are currently no plans to participate in the next round of Iran-US talks".

The Fars and Tasnim news agencies had earlier cited anonymous sources as saying "the overall atmosphere cannot be assessed as very positive", adding that lifting the US blockade was a precondition for negotiations.

State-run IRNA meanwhile pointed to the blockade and Washington's "unreasonable and unrealistic demands", saying that "in these circumstances, there is no clear prospect of fruitful negotiations".

The benchmark US oil contract West Texas Intermediate (WTI) surged 7.5 per cent on Monday, while international oil benchmark Brent North Sea crude gained 6.5 per cent.

Iran and the United States, along with Israel, are just days away from the end of the two-week ceasefire that halted the Middle East war, ignited by surprise US-Israeli strikes on Iran on February 28.

There has so far been only a single, 21-hour negotiating session held in Islamabad on 11 April that ended inconclusively, though groundwork for fresh talks continued afterwards.

"We''re offering a very fair and reasonable DEAL, and I hope they take it," Trump said in a post on Sunday, while also renewing his threats against Iran''s infrastructure if a deal is not made.