LONDON — Britain and Norway announced Monday that they were banding together to bolster Ukraine’s navy, saying that strong maritime forces were critical to countering Russia’s aggression and securing grain and steel shipments through the Black Sea.

As part of the effort, Britain is sending two mine-hunting ships, amphibious armored vehicles and coastal raiding boats to Ukraine, U.K. Defense Secretary Grant Shapps said.

Shapps and Norwegian Defense Minister Bjorn Arild Gram announced the formation of a maritime capability coalition during a news conference in London, saying other nations were expected to join soon, making it a “truly global affair.’’

The European commitment to Ukraine in the face of Russian President Vladimir Putin’s invasion remains firm, despite fears that U.S. funding will be cut off by a political dispute in Congress.

“Securing the seas is the only way to defeat a tyrant like Putin, to guarantee the long-term independence and prosperity for Ukraine and for the whole of Europe,” Shapps said.

British Foreign Secretary David Cameron last week trumpeted the success of Ukraine’s tiny naval forces against Russia’s Black Sea Fleet as an example of why the United States and other democracies should continue to provide military aid to the government in Kyiv.

“Ukraine doesn’t even really have a navy, but they have managed to sink about a fifth of the Russian Black Sea Fleet,” Cameron said at the Aspen Security Forum in Washington. “Well, that is … a remarkable thing.”

The new coalition will work with Ukraine to expand its forces in the Black Sea, develop a Ukrainian Marine Corps and enhance the use of river patrol craft to defend inland and coastal waterways, British authorities said.

The package of U.K. aid announced on Monday includes 20 Viking armored personnel vehicles, which can be deployed rapidly using helicopters or landing craft and 23 coastal raiding boats that can be used to land small detachments of troops or as a firing platform for heavy machine guns.

Britain also said it had transferred two Sandown class vessels, which are designed to help clear mines from coastal waters, to Ukraine.

But deployment of the craft has been stalled by Turkey’s decision to prevent ships not based in the Black Sea from passing through the Bosporus Strait — a move designed to prevent the body of water from becoming a theatre of war.

Britain first announced a deal to sell the two mine-hunting ships to Ukraine in June 2021, before Russia’s full-scale invasion of Ukraine. Ukrainian personnel began training on the ships last year in Scotland.

“Our goal is to contribute to building a lasting Ukrainian naval capability,’’ Norway’s defense minister said. “In the further work, I hope Norway, as a sea-faring nation, can contribute with maritime expertise, new technological solutions and innovative thinking.”