In his first public comments after the 21-hour talks, Trump sought to exert strategic control over the waterway that was responsible for the shipping of 20% of global oil supplies before the war, hoping to eliminate Iran’s key source of leverage.

The prospect of a U.S. blockade could further rattle global energy markets and prices for oil, natural gas and related products. It was not immediately clear how a blockade might be carried out, but Trump said the goal of the blockade was to ensure all ships could transit: “It’s going to be all or none, and that’s the way it is.”

Trump said he has “instructed our Navy to seek and interdict every vessel in International Waters that has paid a toll to Iran. No one who pays an illegal toll will have safe passage on the high seas.” Other nations would be involved in the blockade, he said, but did not name them.

Trump stressed that Tehran’s nuclear ambitions were at the core of the failure to end the war, and the U.S. was ready to “finish up” Iran at the “appropriate moment.”

No word on what happens after ceasefire expires

Face-to-face talks ended earlier Sunday, the highest-level negotiations between the longtime rivals since the 1979 Islamic Revolution. Both delegations later left Islamabad.

Neither side indicated what will happen after the 14-day ceasefire expires on April 22. Pakistani mediators urged all parties to maintain it. Both sides said their positions were clear and blamed the other, underscoring how little the gap had narrowed.

“We need to see an affirmative commitment that they will not seek a nuclear weapon, and they will not seek the tools that would enable them to quickly achieve a nuclear weapon,” Vice President JD Vance, leading the U.S. side, said afterward.

Iran’s parliament speaker Mohammad Bagher Qalibaf, who led Iran in talks, said it was time for the United States “to decide whether it can gain our trust or not.” Iranian officials earlier said talks fell apart over two or three key issues, blaming what they called U.S. overreach.

Pakistani Foreign Minister Ishaq Dar said his country will try to facilitate a new dialogue between Iran and the U.S. in the coming days.

Iran said it was open to continuing the dialogue, Iran’s state-run IRNA news agency reported.

The European Union urged further diplomatic efforts. The foreign minister of Oman, on the southern coast of the Strait of Hormuz, called for both parties to “make painful concessions.” And the Kremlin said Russian President Vladimir Putin had “emphasized his readiness” to help bring about a diplomatic settlement in a call with Iran’s president.

Iran’s nuclear program is a key sticking point

Since the U.S. and Israel launched the war on Feb. 28, the fighting has killed at least 3,000 people in Iran, 2,020 in Lebanon, 23 in Israel and more than a dozen in Gulf Arab states, and caused lasting damage to infrastructure in half a dozen Middle Eastern countries. Iran’s grip on the Strait of Hormuz has largely cut off the Persian Gulf and its oil and gas exports from the global economy, sending energy prices soaring.

Tensions have long centered on Iran’s nuclear program. Tehran has long denied seeking nuclear weapons but insisted on its right to a civilian nuclear program. It has offered “affirmative commitments” in the past in writing, including in the landmark 2015 nuclear deal, which took well over a year of negotiations. Experts say its stockpile of enriched uranium, though not weapons-grade, is only a short technical step away.

An Iranian diplomatic official, speaking on the condition of anonymity because of the sensitivity of closed-door talks, denied that negotiations had failed over Iran’s nuclear ambitions.

“Iran is not seeking to acquire nuclear weapons, but it has the right to nuclear energy for peaceful purposes,” the official said.

In Iran, there was fresh exhaustion and anger after months of unrest that had begun with nationwide protests against economic issues and then political ones, and then weeks of sheltering from U.S. and Israeli bombardment.

“We have never sought war. But if they try to win what they failed to win on the battlefield through talks, that’s absolutely unacceptable,” 60-year-old Mohammad Bagher Karami said in Tehran.

US moves to shift status quo in Strait of Hormuz

During the talks, the U.S. military said two destroyers transited the critical strait ahead of mine-clearing work, a first since the war began. Iran’s state media said the country’s joint military command denied that.

Before talks began, the ceasefire was already threatened by other deep disagreements and Israel’s continued attacks against the Iranian-backed Hezbollah in Lebanon.

Iran’s 10-point proposal had called for a guaranteed end to the war and sought control over the Strait of Hormuz. It wanted the end of fighting against Iran’s “regional allies,” explicitly calling for a halt to Israeli strikes on Hezbollah.

Pakistani officials earlier told The Associated Press that the U.S. 15-point proposal included a rollback of Iran’s nuclear program. Speaking on condition of anonymity as they weren’t authorized to discuss details, they said it also covered reopening the Strait of Hormuz.

Israel presses ahead with strikes in Lebanon

The impasse raises new questions about Lebanon. Israel has said the agreement did not apply there, but Iran and Pakistan claimed otherwise. Negotiations between Israel and Lebanon are expected to begin Tuesday in Washington after Israel’s surprise announcement authorizing talks despite their lack of official relations.

The day the Iran ceasefire deal was announced, Israel pounded Beirut with airstrikes, killing more than 300 people in the deadliest day in Lebanon since the war began, according to the country’s Health Ministry.

Though Israel’s strikes over Beirut have calmed, its attacks on southern Lebanon have intensified alongside the ground invasion it renewed after Hezbollah launched rockets toward Israel in the war’s opening days.

Lebanon’s state-run National News Agency reported six people were killed Sunday in an Israeli strike in Maaroub village near the coastal city of Tyre.

Israel wants Lebanon’s government to assume responsibility for disarming Hezbollah, but the militant group has survived efforts to curb its strength for decades.