The U.S. resumed its naval blockade of Iranian ports, oil terminals, and coastal areas Tuesday as hostilities flared following the collapse of a memorandum of understanding signed between the adversaries last month.

The blockade applies to vessels entering or leaving Iranian ports regardless of the flag they fly.

"U.S. forces resumed the naval blockade against vessels transiting to and from Iranian ports and coastal areas today at 4 p.m. ET," U.S. Central Command wrote on X. "There are currently more than 20 U.S. Navy warships and hundreds of military aircraft operating across the Middle East. American forces remain vigilant, lethal, and ready."

The blockade resumed as the U.S. military launched several strikes on Iran and Tehran responded with attacks on U.S. allies in the region.

About an hour before the blockade began, CENTCOM wrote on X that U.S. forces "began launching an additional round of strikes against Iran to continue degrading Iranian capabilities used to attack commercial shipping in the Strait of Hormuz."

"The strikes are taking place as American forces prepare to resume the naval blockade against Iranian ports and coastal areas," CENTCOM wrote.

CENTCOM said in another X post that U.S. forces struck several areas in Iran during a five-hour mission Monday night.

"U.S. forces successfully struck military targets across Iran including Bushehr, Chabahar, Jask, Konarak, Abu Musa, and Bandar Abbas to further degrade Iran's ability to attack commercial shipping," CENTCOM said.

"CENTCOM forces employed precision munitions against Iranian coastal defense systems, missile and drone sites, and maritime capabilities," it added.

Iran's Islamic Revolutionary Guard Corps said earlier Tuesday that it struck "two non-compliant" supertankers in the strait, according to the state-run Mehr News Agency. Iran also said it launched missiles and drones at U.S. military infrastructure in Bahrain, where the U.S. Navy's 5th Fleet is stationed, and U.S. military outposts in Jordan.

The United Arab Emirates' Defense Ministry said two Emirati-owned tankers were targeted by Iranian cruise missiles while transiting the strait's shipping lane in Omani waters. One person was killed.

Bahraini authorities sounded sirens and urged residents to seek shelter. Jordanian state media said the country's air defenses intercepted four Iranian missiles early Tuesday as they entered its airspace.

Iranian Deputy Foreign Minister Kazem Gharibabadi accused Washington on Tuesday of trying to prevent Tehran from exercising what he called "effective sovereignty" over the Strait of Hormuz.

"The passage of vessels is not important to the U.S. The U.S. is not dependent on the Strait of Hormuz, and Trump has announced it many times," Gharibabadi said in an interview aired by Iran's state broadcaster.

The U.S. first imposed the blockade April 13 and lifted it June 18, a day after the MOU was signed. As part of the deal, Iran guaranteed commercial vessels safe passage through the strait without charging tolls and committed not to develop a nuclear weapon or advance its nuclear program during the 60-day period. In exchange, the U.S. agreed to lift oil sanctions and end the naval blockade.

The U.S. considers the Strait of Hormuz an international waterway where vessels have a right of transit passage. Tehran, however, has asserted control over the vital chokepoint through which roughly 20% of the world's traded crude oil and natural gas passed before the war.

Tehran has insisted that ships obtain permission and follow approved routes. Iran has attacked ships it said failed to comply with its orders and at times has declared the strait closed.

President Donald Trump warned Tuesday that the United States would strike bridges and power plants in Iran "next week" unless Tehran returns to the negotiating table.

"We're going to hit them very hard tomorrow night. We're going to hit them very hard the night after, and then next week it gets really bad for them, because next week comes the power plants. Next week comes the bridges. We're going to knock out all their power plants. We're going to knock out all their bridges unless they get to the table and negotiate," Trump said, according to CNN.

On Monday, Iranian Army spokesman Brig. Gen. Mohammad Akrami-Nia warned the U.S. that no measure of aggression would force the reopening of the strait.

"The aggressive and corrupt president of the United States must learn to respect international law, the rights of nations and the dignity of peoples. As we have previously stated, the Strait of Hormuz will never be reopened through war, hostility, or acts of aggression by the United States," Akrami-Nia said, according to state-run Press TV.