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

Russian President Vladimir Putin held a phone call Sunday with his Iranian counterpart, President Masoud Pezeshkian, offering his support after negotiations between the U.S. and Iran failed to reach an agreement to end the conflict, despite 21 hours of trilateral talks in Pakistan.

According to the Kremlin, Putin said he was ready to mediate a settlement to the war.

"Vladimir Putin emphasized his readiness to continue to facilitate the search for a political and diplomatic settlement to the conflict and to mediate efforts to establish a just and lasting peace in the Middle East" the Kremlin said in its readout of the call.

According to Iran's semi-official news agency, Tasnim, Pezeshkian told Putin that U.S. "double standards" and a "totalitarian approach" remain the main obstacles to reaching a fair agreement in talks between Tehran and Washington.

"The Islamic Republic of Iran is fully prepared to reach a balanced and fair agreement that ensures lasting peace and security in the region. If the United States adheres to international legal frameworks, reaching an agreement is not far off," Pezeshkian said, according to Tasnim.

President Donald Trump and Vice President JD Vance have both said that Iran's alleged refusal to abandon its nuclear program is the main sticking point in the peace talks. Trump said in a Sunday post on his social media platform that "most points were agreed to" during the talks Saturday, but further said that the agreements "don't matter" if Iran is allowed to have nuclear power.

-ABC News' Claire Bower and Dragana Jovanovic

Israeli forces have killed at least 2,055 people and wounded another 6,588 in Lebanon since March 2, according to the latest tally from the Lebanese Ministry of Public Health.

Over the past 24 hours, 35 people were killed and 152 others were injured, the health ministry said Sunday.

Among those killed since March 2 were 165 children and 87 health care workers, the health ministry said. Meanwhile, another 644 children and 190 health care workers were among the injured, according to the health ministry.

-ABC News' Morgan Winsor and Ghazi Balkiz

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!"