The US president also wrote on Truth Social that the blockade of Iranian ports will continue until Tehran presents a "unified proposal".
US-President Donald Trump has announced on Truth Social that he was extending the ceasefire with Iran to give more time for negotiations, but would maintain a US naval blockade of the country's ports.
Trump posted on social media that he would "extend the Ceasefire" until Iran came up with a proposal to end the conflict. However, he "directed our Military to continue the Blockade."
Vice President JD Vance, expected to lead the US negotiating team, called off a trip to Pakistan, a US official said and Iran said it hadn't decided whether or not to participate.
Pakistani leaders, including Prime Minister Shehbaz Sharif, worked intensively late on Tuesday to get both sides to agree to a second round of ceasefire talks, according to two officials who spoke on condition of anonymity because they were not authorised to speak to the media.
Iranian Foreign Ministry spokesman Esmail Baghaei told Iran’s state TV there has been “no final decision” on whether to attend because of “unacceptable actions" by the US, apparently referencing its recent blockade in the Strait of Hormuz.
As Vance put on hold traveling for more ceasefire talks, Trump’s special envoy Steve Witkoff and son-in-law Jared Kushner were expected in Washington on Tuesday afternoon for consultations about how to proceed, an official said.
Earlier on Tuesday, US President Donald Trump said: "We're going to end up with a great deal. I think they have no choice," Trump said, "We're in a very, very strong negotiating position."
Trump is demanding Iran give up its uranium stockpile and end attempts to control the strategic Hormuz waterway used to transport Middle East oil and other commodities.
Despite being hit by weeks of US and Israeli bombing before a temporary ceasefire was declared, Iran has so far refused those conditions.
Asked if he would carry out his previous threats to bomb Iran's bridges and power plants, something many analysts say could constitute war crimes, Trump said "it's not my choice but it will also hurt them."
He said the US had intercepted a ship carrying a "gift" to Iran from China as Tehran tries to restock its military during the ceasefire.
The ship had "a gift from China" which "wasn't very nice," Trump said. "I was a little surprised," he added, saying he thought he had an "understanding" with China's President Xi Jinping.
A week ago, Trump announced that Xi had assured him there would be no Chinese weapons deliveries to Iran, a close partner with Beijing for years.
Growing uncertainty
Tehran and Washington have accused each other of breaching the two-week truce.
During initial talks in Pakistan earlier this month, the highest-level discussions between the foes since the founding of the Islamic Republic in 1979, analysts pointed to the seniority of the delegations as an indicator of a willingness to strike a deal.
But those talks collapsed without an agreement, with Iran since closing the Strait of Hormuz again, and US President Donald Trump announcing a blockade of Iranian ports.
The White House said Vice President JD Vance was ready to fly back to Islamabad to lead the US delegation, which would also include Trump's special envoy Steve Witkoff and the president's son-in-law Jared Kushner.
The talks were initially planned to take place in Islamabad on Monday, but were disrupted after Iran announced its withdrawal, partly prompted by the US seizure of an Iranian-flagged cargo vessel en route to a port on Sunday.
The US Navy said the ship had not complied with its warnings and was attempting to evade its blockade of Iranian ports.
The blockade came into effect last week in response to Iran's closing of the Strait of Hormuz since the beginning of the war on 28 February, which sent oil prices spiralling worldwide.
Iran said the naval blockade of its ports is a violation of the ceasefire agreement, which the US refutes. Trump insisted that the US Navy will continue to enforce it until Iran reopens the strategic waterway it controls to maritime traffic, without conditions.
Tehran also said it refused to engage in any diplomatic efforts under the threat of attack, after Trump, in various posts on social media over the last few days, vowed to intensify the fighting and “blow up” the entire country if it fails to enter into a deal with Washington.
"Trump, by imposing a siege and violating the ceasefire, seeks to turn this negotiating table — in his own imagination — into a table of surrender or to justify renewed warmongering," wrote Iran's parliament speaker Mohammad Bagher Ghalibaf on X on Monday.
"We do not accept negotiations under the shadow of threats, and in the past two weeks, we have prepared to reveal new cards on the battlefield," he added.