More than 20 nations are said to have offered to contribute assets to the US-led military operation to protect commercial shipping in the Red Sea, a top US official has confirmed.

Major General Pat Ryder, press secretary for the Pentagon, said contributions range from ships and aircraft to other contributions including staff and other types of support.

“In the days ahead, the US will continue to consult closely with our allies and partners who share the fundamental principle of freedom of navigation, and we expect to see the coalition continue to grow,” Ryder said.

He told a press briefing at the Pentagon that the operation was a “global answer to an international issue and the US will continue to work with this coalition of the willing where countries will be able to contribute what they feel that they can”.

Convoys appear to have been ruled out at this stage with Ryder saying that the forces assigned to Operation Prosperity Guardian, will serve as the “highway patrol” in the Red Sea and the Gulf of Aden.

He said naval forces would “respond to and assist as necessary commercial vessels that are transiting this vital international waterway”.

“It’s a defensive coalition meant to reassure global shipping and mariners that the international community is there to help with safe passage,” the general added.

“It’s very important to understand that the Houthis aren’t attacking just one country, they’re really attacking the international community,” Ryder said.

“They are attacking the economic well-being and prosperity of nations around the world. So, in effect, they become bandits along the international highway that is the Red Sea.”

Ryder said that the Houthis need to stop these attacks, and they need to “stop them now”.

“They really need to ask themselves if they’ve bitten off more than they can chew when it comes to taking on the entire international community and negatively impacting billions of dollars in global trade, economic prosperity and international law,” he said.