A Yemeni Houthi official said on Sunday that the Iran-aligned group's response to the U.S. attack on Iran was "only a matter of time."
Mohammed al-Bukhaiti, a member of the Houthi movement's political bureau, told Al Jazeera Mubasher TV that its ceasefire deal with Washington was before the "war" on Iran.
The group has been launching attacks on shipping lanes and Israel in what it says is in solidarity with Palestinians in Gaza during the Israeli war. It agreed on a ceasefire deal with the United States in May to stop attacking U.S. ships in exchange for an end to Washington's bombings of the group.
The multinational, U.S.-led combined maritime force's JMIC information centre said it has categorized the threat to U.S. associated commercial shipping in the Red Sea and Gulf of Aden as "high" after U.S. strikes on Iranian nuclear facilities.
German shipping company Hapag-Lloyd on Sunday said its vessels were continuing to sail through the Strait of Hormuz following U.S. strikes on Iranian nuclear facilities overnight, but it added the situation could be reviewed at any moment.
Maersk vessels continue to sail through the Strait of Hormuz but the company was ready to re-evaluate this based on available information, the group said in a statement on Sunday.
"We will continuously monitor the security risk to our specific vessels in the region and are ready to take operational actions as needed," the Danish container shipping company said.
Japan's Nippon Yusen and Mitsui O.S.K. Lines said on Monday they have instructed their vessels to minimise the time spent in the Gulf as they continue to transit the Strait of Hormuz.
Iran's top security body must make the final decision on whether to close the Strait of Hormuz, Iranian TV said on Sunday, after parliament reportedly backed the measure.
Iran has in the past threatened to close the strait but has never followed through on the move, which would restrict trade and impact global oil prices.
WHAT IS THE STRAIT OF HORMUZ?
The strait lies between Oman and Iran and links the Gulf north of it with the Gulf of Oman to the south and the Arabian Sea beyond.
It is 21 miles (33 km) wide at its narrowest point, with the shipping lane just 2 miles (3 km) wide in either direction.
WHY DOES IT MATTER?
About a fifth of the world's total oil consumption passes through the strait. Between the start of 2022 and last month, somewhere between 17.8 million and 20.8 million barrels of crude, condensate and fuels flowed through the strait daily, data from analytics firm Vortexa showed.
OPEC members Saudi Arabia, Iran, the United Arab Emirates, Kuwait and Iraq export most of their crude via the strait, mainly to Asia. The UAE and Saudi Arabia have sought to find other routes to bypass the strait.
About 2.6 million barrels per day (bpd) of unused capacity from existing UAE and Saudi pipelines could be available to bypass Hormuz, the U.S. Energy Information Administration said in June last year.
Qatar, among the world's biggest liquefied natural gas exporters, sends almost all of its LNG through the strait.
The U.S. Fifth Fleet, based in Bahrain, is tasked with protecting commercial shipping in the area.
HISTORY OF TENSIONS
In 1973, Arab producers led by Saudi Arabia slapped an oil embargo on Western supporters of Israel in its war with Egypt.
While Western countries were the main buyers of crude produced by the Arab countries at the time, nowadays Asia is the main buyer of OPEC's crude.
The U.S. more than doubled its oil liquids production in the last two decades and has turned from the world's biggest oil importer into one of the top exporters.
During the 1980-1988 Iran-Iraq War, the two sides sought to disrupt each other's exports in what was called the Tanker War.
In July 1988, a U.S. warship shot down an Iranian airliner, killing all 290 aboard, in what Washington said was an accident and Tehran said was a deliberate attack.
In January 2012, Iran threatened to block the strait in retaliation for U.S. and European sanctions. In May 2019, four vessels - including two Saudi oil tankers - were attacked off the UAE coast, outside the Strait of Hormuz.
Three vessels, two in 2023 and one in 2024, were seized by Iran near or in the Strait of Hormuz. Some of the seizures followed U.S. seizures of tankers related to Iran.
WHAT ARE THE MAIN US MILITARY BASES IN THE MIDDLE EAST?
BAHRAIN: Home to the headquarters of the U.S. Navy's Fifth Fleet, whose area of responsibility includes the Gulf, Red Sea, Arabian Sea and parts of the Indian Ocean.
QATAR: The 24-hectare Al Udeid Air Base, in the desert outside the capital Doha, is the forward headquarters for U.S. Central Command, which directs U.S. military operations in a huge swathe of territory stretching from Egypt in the west to Kazakhstan in the east. The Middle East's largest U.S. base houses around 10,000 troops.
KUWAIT: Several sprawling military installations include Camp Arifjan, the forward headquarters of U.S. Army Central and the Ali Al Salem Air Base, roughly 40 kilometers from the Iraqi border and known as "The Rock" for its isolated, rugged environment. Camp Buehring was established during the 2003 Iraq War and is a staging post for U.S. Army units deploying into Iraq and Syria, according to the U.S. Army website.
UNITED ARAB EMIRATES: The Al Dhafra Air Base, situated south of UAE capital Abu Dhabi and shared with the UAE Air Force, is a critical U.S. Air Force hub that has supported key missions against the Islamic State, as well as reconnaissance deployments across the region, according to the U.S. Air Force Central Command.
Dubai's Jebel Ali Port, while not a formal military base, is the U.S. Navy's largest port of call in the Middle East that regularly hosts U.S. aircraft carriers and other vessels.
IRAQ: The U.S. maintains a presence at Ain Al Asad Air Base in western Anbar province, supporting Iraqi security forces and contributing to the NATO mission, according to the White House. Iranian missile strikes targeted the base in 2020, in retaliation for the U.S. killing of Iranian General Qasem Soleimani.
Situated in the semi-autonomous Kurdistan Region of northern Iraq, Erbil Air Base serves as a hub for U.S. and coalition forces conducting training exercises and battle drills. The base supports U.S. military efforts by providing a secure location for training, intelligence sharing, and logistical coordination in northern Iraq, according to the congressional report.
SAUDI ARABIA: U.S. soldiers in Saudi Arabia -- which numbered 2,321 in 2024 according to a White House letter -- operate in coordination with the Saudi government, providing air and missile defense capabilities and support the operation of U.S. military aircraft.
Some are stationed roughly 60 kilometres south of Riyadh, at Prince Sultan Air Base, which supports U.S. Army air defense assets including Patriot missile batteries and Terminal High Altitude Area Defense systems.
JORDAN: Located in Azraq, 100 kilometres northeast of the capital Amman, the Muwaffaq al Salti Air Base hosts the U.S. Air Forces Central's 332nd Air Expeditionary Wing, which engages in missions across the Levant, according to a 2024 report in the library of Congress.
(Reporting by Reuters)