LONDON (AP) — Britain and Norway will mount joint naval patrols to protect undersea cables from Russia, the U.K. said Thursday, as Prime Minister Keir Starmer and Norwegian counterpart Jonas Gahr Støre held talks on defense.

The U.K. government says a combined fleet of at least 13 warships will “hunt Russian submarines and protect critical infrastructure in the North Atlantic.”

It follows a 10 billion pound ($13.4 billion) deal struck in August for Norway to buy at least five British-made frigates. Those Norwegian vessels and eight British ships will operate jointly in the seas along NATO’s northern flank.

As part of the agreement, formally signed Thursday in London by the two countries’ defense ministers, the U.K. has agreed to use Norwegian missiles for the Royal Navy’s surface fleet.

Starmer and Støre were scheduled to hold talks at the U.K. prime minister's residence at 10 Downing St. before visiting British and Norwegian personnel at RAF Lossiemouth in Scotland, where they will meet aircraft crews that have been tracking Russian vessels. Britain says Russian naval activity around U.K. waters has increased by 30% in the past two years.