The United States condemned "unprecedented" attacks by Yemeni rebels on Red Sea shipping as the Huthis pledged Tuesday to continue military operations despite the announcement of a new maritime protection force.
The flurry of drone and missile attacks by the rebels, the latest of which targeted two vessels on Monday, threaten to upend global trade flows, with major shipping firms halting traffic through the Bab al-Mandeb strait.
Pentagon chief Lloyd Austin warned Tuesday that the attacks "threaten" the free flow of commerce, a day after he announced a multinational task force to quell Huthi missile and drone attacks.
"Secretary Austin condemned Huthi attacks on international shipping and global commerce as unprecedented and unacceptable, noting the attacks threaten the free flow of commerce," Pentagon press secretary Major General Pat Ryder said in a statement.
Austin spoke during a virtual meeting with representatives of 43 countries, as well as the European Union and NATO, to discuss the increased threat to maritime security in the Red Sea, the statement said.
The Pentagon chief "urged participants to join US-led and other international initiatives... to restore security in the Red Sea to deter future Huthi aggression," the statement added.
The task force he announced on Monday includes Britain, Canada, France, Italy, the Netherlands, Norway and Spain as well as the United States.
It drew Huthi ire, with rebels pledging to continue attacks.
"Even if America succeeds in mobilising the entire world, our military operations will not stop... no matter the sacrifices it costs us," senior Huthi official Mohammed al-Bukhaiti said on X, formerly Twitter.
Rebel spokesman Mohammed Abdul Salam said the "US-formed coalition aims to protect Israel and militarise the sea," adding: "Whoever seeks to expand the conflict must bear the consequences of those actions."
Yemen's Huthi rebels have launched more than 100 drone and missile attacks, targeting 10 merchant vessels involving more than 35 different countries, according to the Pentagon.
In November, they seized the Galaxy Leader merchant vessel, taking its 25-member crew hostage. Both the vessel and crew remain in Yemen.
- 'Difficult to intercept' -
On Monday, the rebels claimed attacks on two vessels in the vital shipping lane between Asia and Europe, including the Norwegian-owned Swan Atlantic.
The US military's Central Command said the Swan Atlantic "was attacked by a one-way attack drone and an anti-ship ballistic missile launched from Huthi-controlled areas in Yemen".
It said the guided missile destroyer USS Carney "responded to assess damage".
At approximately the same time, "the bulk cargo ship MV Clara reported an explosion in the water near their location," CENTCOM said.
No casualties were reported in either attack, it added.
Insurance costs have soared, prompting major shipping firms to reroute their vessels around the southern tip of Africa, despite the higher fuel costs of the much longer voyage.
Denmark's A.P Moller-Maersk -- which accounts for 15 percent of global container freight -- is among the shipping giants that have suspended Red Sea voyages until further notice.
In a statement on Tuesday, it said "all vessels previously paused and due to sail through the region will now be rerouted around Africa via the Cape of Good Hope."
As of Monday, "Maersk had approximately 20 vessels that had paused transits, out of which half were waiting".
According to analysts, the maritime task force announced by Washington can do little to halt attacks by the Huthi rebels, who command an arsenal of ballistic missiles, cruise missiles and drones.
"The Huthis have an extended arsenal of different drones and missiles that they can shoot... and some of them will be difficult to intercept by your average navy ship," Andreas Krieg, a professor at King's College London, told AFP.
Torbjorn Soltvedt of the risk intelligence firm Verisk Maplecroft said the "threat to shipping is also further increased by the group’s ability to deploy anti-ship mines and execute coordinated operations using boats and helicopters."