“Spain will never participate in an operation from a unilateral point of view. All decisions will always be taken under the umbrella of the European Union and NATO,” government spokeswoman Pilar Alegria told a news conference.

The United States on Monday announced a 10-nation coalition to quell the Huthi missile and drone attacks on ships transiting the Red Sea, with Britain, France, Bahrain and Italy among countries joining the “multinational security initiative.”

US Defense Secretary Lloyd Austin said the security coalition also included the United States, Canada, Netherlands, Norway, Seychelles and Spain.

But Spain’s defence ministry said Tuesday the country “depends on the decisions of the European Union and NATO and, therefore, will not participate unilaterally.”

The head of Spain’s conservative opposition Popular Party (PP), Alberto Núñez Feijóo, told a separate news conference that Prime Minister Pedro Sánchez had told him that Madrid had “decided not to intervene, at least not intervene in the conditions requested by the United States”. He did not elaborate.

Yemen’s Iran-backed Huthi rebels have launched a flurry of drone and missile attacks on vessels passing through the Red Sea, aimed at pressuring Israel over its devastating war with Hamas in the Gaza Strip.

The drone and missile attacks by the rebels are imperilling a transit route that carries up to 12 percent of global trade.