US President Donald Trump on Tuesday accused Iran of having repeatedly violated a temporary truce due to expire soon, with new peace talks mired in doubt after Tehran said it had not yet sent a delegation.
The US leader also touted Washington's strong negotiating position, even as uncertainty grew over a push to stop open conflict from resuming, with the two-week ceasefire set to end by Wednesday.
"Iran has Violated the Cease Fire numerous times!" Trump said in a post on his Truth Social platform, without elaborating.
A US delegation led by Vice President JD Vance was expected to leave soon for Islamabad, which earlier this month hosted a first round of talks that ended without a deal.
Since those marathon talks Trump has announced a blockade of Iranian ports, while Tehran has closed the Strait of Hormuz again, refusing to send officials for a new round of negotiations that were initially expected on Monday.
"So far, no delegation from Iran has departed for Islamabad, Pakistan," Iranian state TV said on Tuesday, dismissing reports suggesting otherwise.
Both sides have accused the other of ceasefire breaches, with the US leader saying Iran fired on ships in the crucial trade route it has choked, and Tehran calling the US blockade and its seizure of a ship violations as well.
Despite Tehran so far shunning new talks, Trump expressed confidence he could secure an agreement that favored Washington.
"We're going to end up with a great deal. I think they have no choice... We're in a very, very strong negotiating position," Trump told broadcaster CNBC on Tuesday.
"Iran can get themselves on a very good footing if they make a deal."
Pakistan, meanwhile, continued its down-to-the wire mediation efforts to get both sides to its capital.
Foreign Minister Ishaq Dar urged the warring parties "to consider extending the ceasefire and to give dialogue and diplomacy a chance," according to a Pakistani foreign ministry statement.
Iranian officials, however, say they feel the Trump administration has not acted in good faith in negotiations and has refused to back down from what they called excessive demands.
Its parliament speaker said the country would not accept talks "under the shadow of threats" from the US leader, and would "show new cards on the battlefield" if the conflict resumed.
- 'Bombs start' -
Residents in the Iranian capital who spoke to Paris-based AFP journalists say life has only got worse despite the truce, squeezed by the government and the war's impact.
"This cursed ceasefire has broken us. There is no light at the end of the tunnel," said Saghar, 39.
"The situation is terrible. I don't know anyone around me who is doing well."
The truce theoretically ends overnight Tuesday, though in comments to Bloomberg, Trump said the end was a day later, on Wednesday evening Washington time, and that it was "highly unlikely" he would extend it.
Trump told PBS News that Iran was "supposed to be there" at the talks in Pakistan.
He warned that if the ceasefire expired "then lots of bombs start going off."
He also said the US blockade of Iran's ports would not end until there was a deal.
The US Defense Department said Tuesday that its forces intercepted and boarded a "stateless sanctioned" vessel as part of Washington's efforts against networks that provide support to Iran.
AFP has identified the vessel as one affiliated with Iranian activity.
Experts said Iran's noncommittal public stance was part of a bid to put pressure on Washington.
"The current standoff between the United States and Iran is no longer a clash of capabilities but rather a struggle of political endurance and bargaining leverage," Daniel Byman of the Center for Strategic and International Studies wrote in a commentary.
Despite the ongoing uncertainty, oil prices fell on Tuesday while stocks rose on lingering hopes for a deal to end the conflict.
- Tight security -
In Islamabad, heavily armed police and soldiers on Tuesday secured the city's government quarter, which was virtually shut down.
That included the Serena hotel, which hosted the last round of negotiations and where guests had been asked to vacate the premises in recent days.
The rest of the city also saw a beefed-up police presence, with offices, businesses and schools braced for shutdown orders.
In another arena in the war, Israel and Lebanon, which have no diplomatic relations, will hold fresh talks in Washington on Thursday, a State Department official told AFP.
A separate 10-day ceasefire was agreed between the two nations on Friday and included Hezbollah, whose rocket fire in support of Iran drew Lebanon into the wider Middle East conflict.
Sporadic violence has continued and Israel's military warned civilians against returning to dozens of villages in southern Lebanon, claiming Hezbollah's activities were violating the truce.
Israeli attacks on Lebanon have killed at least 2,387 people since the start of the war, a Lebanese government body said in its latest toll.
