Attacks on commercial ships in the Red Sea risk pushing up the price of oil and other goods, analysts have warned.
Several firms have paused shipments through the route after vessels were attacked by Houthi rebels in Yemen.
The world’s second largest shipping line, Maersk, said on Tuesday that it would reroute some of its vessels around Africa’s Cape of Good Hope.
The disruption has led the US to launch an international naval operation to protect ships on the Red Sea route.
Countries joining the security action – named Operation Prosperity Guardian – include the UK, Canada, France, Bahrain, Norway and Spain.
The US has also said it would welcome China playing a constructive role in trying to prevent further attacks.
The analysts’ warnings came as the rebels vowed to continue their attacks in the Bab al-Mandeb strait, a vital shipping lane between Asia and Europe.
“Even if America succeeds in mobilising the entire world, our military operations will not stop… no matter the sacrifices it costs us,” said senior Houthi official Mohammed al-Bukhaiti on X, formerly Twitter.
What is the impact of the Red Sea attacks?
US defence secretary Lloyd Austin held a virtual meeting with ministers from more than 40 countries on Tuesday, and called on more nations to contribute to the security efforts.
“These reckless Houthi attacks are a serious international problem and they demand a firm international response,” he said.
The UK’s Ministry of Defence said the Royal Navy destroyer HMS Diamond would join the new task force, with the security situation “deteriorating”.
The Red Sea is one of the world’s most important routes for oil and liquefied natural gas shipments, as well as for consumer goods. It is bookended by the Bab al-Mandab Strait – also known as the Gate of Tears – in the south near the coast of Yemen and the Suez Canal in the north.
Houthis have declared their backing for Hamas in its war with the Israelis and the rebels based in Yemen said they were targeting vessels which they believe are heading for Israel.
However, some firms, such as Investor Chemical Tankers, whose Swan Atlantic vessel was attacked on Monday, said that its ship had no links to Israel.
Shipping firms have reported vessels coming under attack from drones and missiles.
“The ballistic missiles are really the tough one. This is the first time we’ve ever seen ships hit by this type of weapon,” Sal Mercogliano, a naval historian at Campbell University, told the BBC.
“It’s a very difficult type of missile to shoot down.”
Despite the launch of the international operation to ensure safe passage through the Red Sea, Maersk said it was not clear when it would resume journeys along the route, and would assess things on a case-by-case basis.
It said while it was pleased to hear of efforts to improve security in the area, “at this time it remains difficult to determine” when it would return to the Red Sea route.
Meanwhile, Hapag-Lloyd, a German firm whose Al Jasrah vessel was attacked last Friday, said that while it welcomed the new task force, the company needed 100% assurance the Red Sea was safe for ships to return.
The alternative route, around the Cape of Good Hope, adds about 3,500 nautical miles to the journey.
Hapag-Lloyd’s head of corporate communications Nils Haupt told the BBC: “We go from the eastern Med to Singapore. Normally it takes 13 days through the [Suez] Canal – without using the canal that will be 31 days.”
