Iran threatened to block all oil exporting routes in the region on Wednesday in response to the U.S. maritime blockade of Iranian ports in the Strait of Hormuz.
A statement by the Iranian Revolutionary Guard said the U.S. "must expect other oil and gas export routes that serve the interests of the United States and its allies to be closed as well."
"The region's oil and gas exports will either be available to everyone or to no one," said the statement carried by Iranian state media.
Though it did not make a direct reference to the Bab al-Mandab Strait, in the past Iran has threatened to close off the narrow passage at the entrance of the Red Sea, which links up to the Suez Canal as well as to the Gulf of Aden and the Indian Ocean, providing passage to commercial vessels between Europe, Asia and Africa.
The U.S. military said it began another wave of strikes on Wednesday morning "to further degrade military capabilities Iranian forces have used to attack commercial shipping in the Strait of Hormuz."
The escalation entered its fifth day on Wednesday, raising the specter of a return to all-out war in the region, which began on Feb. 28 after the U.S. and Israel launched strikes on Iran. The stepped up attacks in the past week have left their tentative ceasefire in tatters with no sign of progress toward a final deal to end the war.
This latest round followed back and forth strikes overnight as the U.S. military reimposed the blockade of Iranian vessels in the strait. Iran responded with retaliatory strikes targeting U.S. military bases in Kuwait, Bahrain and Jordan.
Adm. Brad Cooper, who commands the U.S. Central Command, accused Iran of attacking seven commercial ships and launching missiles against Gulf countries.
"U.S. forces are holding Iran accountable for unwarranted aggression that continues to endanger innocent lives," Cooper said in a statement on Tuesday.
Two key international waterways in the region
Control over the Strait of Hormuz has emerged as the key point of contention between the U.S. and Iran. The deadlock over the waterway, through which roughly 20% of the world's energy supplies typically move, has disrupted global trade and increased fuel prices around the world.
Washington sees the Strait of Hormuz as an international waterway, but since the U.S. and Israel launched their war on Iran, Tehran has asserted its control over the strait and has insisted ships get permission and follow approved routes. Iran has been attacking ships if they did not comply with its orders and at times has announced the strait was closed.
Though less trafficked than the Strait of Hormuz, the Bab al-Mandab Strait is also a vital chokepoint for international trade and its possible closure would affect oil exports from the Middle East. About 10 % of the world's oil moves through this strait.
Vessels in the Bab al-Mandab Strait came under attack in 2025 by Iran-backed Houthi rebels in Yemen, as they targeted Israeli vessels and Israel during the Gaza war. The U.S. military launched strikes against the militia group last year in response to Houthi attacks.
The Houthi's Ansar Allah, an armed political and religious group which controls the north and west of Yemen, accused Saudi Arabia of breaking a four-year old ceasefire Monday with an attack on the international airport in the Yemeni capital. Yemen's internationally-recognized government, which is backed by Saudi Arabia, said it carried out the attack itself to prevent an Iranian plane from landing in Sanaa.
That ceasefire was aimed at ending the civil war between the Iran-backed Houthi rebels and a Saudi-led coalition supporting the Yemeni government.
A senior official of Yemen's Houthi rebel government said Monday that it was prepared to close the Bab al-Mandeb Strait in the Red Sea if Saudi Arabia continued attacks on Yemeni infrastructure.
"If the current situation aggravates, the Bab al-Mandeb Strait and the Strait of Hormuz will be closed in an operational alliance," Iranian state TV quoted Mohammad al-Farah, a member of the political bureau of the Ansar Allah movement, as saying.
The Houthis have emerged as a key part of Iran's 'axis of resistance' – carrying out attacks on Israeli-related and U.S. shipping targets since the war in Iran began.
Trump reverses course on strait fees
Just before the U.S. blockade on Iranian ports came into effect on Tuesday, President Trump reversed his decision to impose a 20% cargo charge on ships in exchange for helping them safely transit the Strait of Hormuz.
"Based on highly productive conversations with Middle East leadership, I have decided to replace the 20% United States Reimbursement Fee with Trade and Investment Deals that the various Gulf States will be making into the United States," he wrote online. No further details on the investments have been provided.
Until this week, the U.S. had said there should not be any tolls or fees on shipping through the strait. Trump's online post Monday saying the U.S. would charge cargo fees caused confusion and concern internationally.
Speaking to reporters in the Oval Office on Tuesday, Trump said he had changed his mind after feedback, particularly from Gulf Arab countries.
"So I put it out yesterday. I thought it was good," Trump said of the idea to charge ships 20% cargo fees in exchange for providing safe passage. "I was called by different people, different countries, kings and emirs, and all of the people that we all know, and we all love, and they've been frankly, they've been very strong partners. And they said we'd love to do it a different way."
He later said, "You have Saudi Arabia, UAE, Qatar, Bahrain and Kuwait, and you know primarily, and then others. They, I spoke to all of them, and they would love to invest more money in the United States at record amounts, and that would be very acceptable. And this way, there's no fee."
But Trump said the blockade was still going ahead.
It follows an earlier U.S. naval blockade on Iran from April 13 to June 18.
Prior to announcing the reinstatement of its blockade, the U.S. had urged ships to use a southern route that hugs the coast of Oman. Iran said this violated the memorandum of understanding.
The U.S. has also accused Iran of breaching the memorandum.
NPR's Hadeel Al-Shalchi and Jane Arraf contributed reporting.
Copyright 2026 NPR