Iran live updates: US blockade of Iran's Strait of Hormuz ports to begin Monday

Despite his announcement Sunday of a U.S. naval blockade of the Strait of Hormuz, President Donald Trump also urged Iran to open the critical maritime waterway in a subsequent post on his social media platform.

"As they promised, they better begin the process of getting this INTERNATIONAL WATERWAY OPEN AND FAST!" Trump wrote, immediately after the post announcing the blockade.

The president claimed that "Iran promised to open the Strait of Hormuz, and they knowingly failed to do so," adding that this has caused "anxiety, dislocation, and pain" to the world.

Trump proceeded to rail against the leaders of Iran, despite his previous insistence that there was regime change there and that the new leaders were more "reasonable."

"There is great dishonor and permanent harm to the reputation of Iran, and what's left of their 'Leaders,' but we are beyond all of that," Trump wrote, adding that they were "very unyielding" during negotiations.

Trump did not go into detail about the negotiations but repeated what Vice President JD Vance said Saturday night about Iran allegedly refusing to give up their nuclear ambitions.

"I could go into great detail, and talk about much that has been gotten but, there is only one thing that matters - IRAN IS UNWILLING TO GIVE UP ITS NUCLEAR AMBITIONS!" the president wrote.

Trump also acknowledged that the "meeting went well" and "most points were agreed to," though he further said that the agreements "don't matter" if Iran is allowed to have nuclear power.

"In many ways, the points that were agreed to are better than us continuing our Military Operations to conclusion, but all of those points don't matter compared to allowing Nuclear Power to be in the hands of such volatile, difficult, unpredictable people," the president wrote.

-ABC News' Emily Chang

President Donald Trump said that the U.S. will "immediately" begin a blockade of the Strait of Hormuz, following the failure of peace negotiations between the U.S. and Iran.

"(T)he meeting went well, most points were agreed to, but the only point that really mattered, NUCLEAR, was not," Trump wrote on his social media platform Sunday. "Effective immediately, the United States Navy, the Finest in the World, will begin the process of BLOCKADING any and all ships trying to enter, or leave, the Strait of Hormuz."

The president did not provide specifics in his social media posts. ABC News has reached out to the White House for comment.

Trump's statement comes after Vice President JD Vance, leading a U.S. delegation for high-stakes talks with Iran, said Saturday that the two sides had not reached a deal despite negotiations lasting some 21 hours in Islamabad, Pakistan. Though he declined to provide specifics about why the negotiations deteriorated, Vance said it was in part because the U.S. did not see the "fundamental commitment" from the Iranians not to develop a nuclear weapon in the long term.

Calling Iran's blockage of the Strait of Hormuz "WORLD EXTORTION," the president also said that he had "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."

"We will also begin destroying the mines the Iranians laid in the Straits," Trump wrote. "Any Iranian who fires at us, or at peaceful vessels, will be BLOWN TO HELL!"

"The Blockade will begin shortly. Other Countries will be involved with this Blockade. Iran will not be allowed to profit off this Illegal Act of EXTORTION," the president wrote. "They want money and, more importantly, they want Nuclear. Additionally and, at an appropriate moment, we are fully 'LOCKED AND LOADED,' and our Military will finish up the little that is left of Iran!"

Vice President JD Vance, leading a U.S. delegation for high-stakes talks with Iran, said the two sides have not reached a deal despite negotiations lasting some 21 hours in Islamabad, Pakistan.

"The bad news is that we have not reached an agreement," Vance said in brief remarks following the conclusion of the talks. "And I think that's bad news for Iran much more than it's bad news for the United States of America. So we go back to the United States having not come to an agreement."

When asked where the negotiations deteriorated, Vance said he wouldn't get into the full details but that the U.S. needed a firm commitment from Iran that it would not seek a nuclear weapon.

"The simple fact is 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," Vance said. "That is the core goal of the President of the United States."

Although Vance said during his remarks that Iran's enrichment facilities have been destroyed, he said the U.S. did not see the "fundamental commitment" from the Iranians not to develop a nuclear weapon in the long term.

"I think that we were quite flexible, we were quite accommodating," Vance told reporters. "The president told us you need to come here in good faith and make your best effort to get a deal."

But he said Iran did not accept U.S. terms.

In addition to Vance, special envoy Steve Witkoff and the president's son-in-law, Jared Kushner took part in the talks.

Vance said the team communicated with President Donald Trump and other members of the Cabinet throughout the negotiation process.

-ABC News' Hannah Demissie and Emily Chang

The trilateral in-person negotiations between the U.S, Iran and Pakistan have continued into the early morning hours, according to the White House.

Asked about the state of ongoing negotiations being led by Vice President JD Vance, a senior White House official told ABC News: "15 hours and counting!"

The statement came shortly after 7:30 p.m. ET, which is 4:30 a.m. in Islamabad where the talks are taking place.

Both sides met first with Pakistani leaders before the historic sitdown Saturday, the highest level face-to-face meeting between the U.S. and Iran in 47 years.

In addition to Vance, special envoy Steve Witkoff and the president's son-in-law, Jared Kushner took part in the talks with top Iranian officials, including the speaker of the Iranian Parliament.