Trump says US Navy attacked and seized Iranian-flagged cargo ship

The spokesperson for Iran's joint military command at Khatam al-Anbiya Central Headquarters said Monday that if the security of Iranian ports in the Persian Gulf and the Sea of Oman is threatened, "no port in the Persian Gulf and the Sea of Oman will be safe."

"Enemy-affiliated" vessels will not have the right to pass through the Strait of Hormuz, while other vessels will continue to be allowed transit "in accordance with the regulations of the Islamic Republic of Iran's armed forces," the spokesperson said, as quoted by Iran's state television Telegram channel.

"Given the continued threats," he said, the Islamic Republic will also implement "a permanent mechanism" to control the Strait of Hormuz, even after the war.

-ABC News' Somayeh Malekian

Iranian Foreign Minister Abbas Araghchi said in a post to X on Sunday night that the U.S. and Iran were "inches away" from a memorandum of understanding in talks in Islamabad at the weekend.

Talks collapsed after Iran "encountered maximalism, shifting goalposts and blockade," Araghchi alleged. "Zero lessons learned," he added.

"In intensive talks at highest level in 47 years, Iran engaged with U.S in good faith to end war," the foreign minister wrote. "Good will begets good will. Enmity begets enmity."

President Donald Trump on Sunday night lashed out against Pope Leo XIV on social media, calling the first-ever American pontiff “weak” over his calls for the U.S. war in Iran to end.

“Pope Leo is WEAK on Crime, and terrible for Foreign Policy,” Trump wrote on social media. The president added, “I don’t want a Pope who thinks it’s OK for Iran to have a Nuclear Weapon.”

In recent weeks, the Pope has criticized the war in Iran and called for peace in the Middle East.

Earlier this month, the Pope asked “all people of goodwill to search always for peace and not violence, to reject war, especially a war which many people have said is an unjust war, which is continuing to escalate and which is not resolving anything.”

And on Saturday, the Pope referred to the U.S. military offensive in Iran as a “delusion of omnipotence,” imploring the country leaders to come to a peace agreement.

-ABC News' Fritz Farrow and Emily Chang

U.S. forces will begin a blockade of maritime traffic to and from Iranian ports Monday morning, according to U.S. Central Command.

"U.S. Central Command (CENTCOM) forces will begin implementing a blockade of all maritime traffic entering and exiting Iranian ports on April 13 at 10 a.m. ET, in accordance with the President’s proclamation," according to a CENTCOM statement late Sunday afternoon.

"The blockade will be enforced impartially against vessels of all nations entering or departing Iranian ports and coastal areas, including all Iranian ports on the Arabian Gulf and Gulf of Oman," the statement continued, adding that CENTCOM forces "will not impede freedom of navigation for vessels transiting the Strait of Hormuz to and from non-Iranian ports."

President Donald Trump said Sunday morning in a post on his social media platform 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.

Commercial mariners will be provided with additional information prior to the start of the blockade, according to CENTCOM, which also advised "all mariners" to monitor advisory broadcasts and contact U.S. naval forces "when operating in the Gulf of Oman and Strait of Hormuz approaches."