The UK will provide two Royal Navy mine hunter ships to protect merchant vessels in Ukraine’s Black Sea trade.

Floating mines representing a big risk for ships calling at Ukraine’s ports in the Danube River and around Odesa, so the move announced on Monday aims to bolster Kyiv’s renascent maritime corridor that has been running since August.

The two Sandown Class mine countermeasures vessels are meant to be the first step in a new Maritime Capability Coalition, led by the UK and Norway.

The ships have glass-reinforced plastic hulls to help conceal their presence from sea mines.

“These minehunters will deliver vital capability to Ukraine, which will help save lives at sea and open up vital export routes, which have been severely limited since [Russian President Vladimir] Putin launched his illegal full-scale invasion [of Ukraine],” UK defence secretary Grant Shapps said.

Ukraine’s President Volodymyr Zelenskyy hailed the move.

“I am grateful to the UK and Norway for launching a new Maritime Capability Coalition to support Ukraine,” he tweeted on X.

According to data compiled by the United Nations, 240 bulkers carrying more than 8.5m tons of grains and iron products left the three main Ukrainian ports of Odesa, Chornomorsk and Yuzhnyy/Pivdennyi between 16 August and 11 December.

A few of them, as well as other smaller vessels trading in the Danube, were hit by sea mines. No considerable damage has been caused in those incidents, however.

Russian missile and drone attacks against Ukrainian port infrastructure, by contrast, have been a far greater risk to commercial shipping in the area.

Ukraine and its backers have long called on Western governments to provide war vessels to protect its fragile maritime trade.

To arrive there, though, warships would have to cross the Bosphorus, which Turkey is obliged by international treaties to keep neutral.

The Turkish government has made no statement yet as to whether it will let the mine sweepers go through. Being of a defensive nature, however, their passage probably causes no diplomatic problems.

Norwegian defence minister Bjorn Arild Gram held out the prospect of further naval support for Ukraine.

“I hope Norway, as a seafaring nation, can contribute with maritime expertise, new technological solutions and innovative thinking,” he said.

The new maritime coalition will aim, among other things, to help develop “a maritime force in the Black Sea”, expand Ukraine’s Marine Corps and provide river patrol craft to defend coastal and inland waters.