LONDON/OSLO – Britain and Norway have signed a £10 billion ($13.5 billion) defence agreement to bolster maritime security and counter the growing threat from Russia. The deal, finalized on Thursday, September 4, marks Norway’s largest-ever military investment.

Under the agreement, Norway will acquire new anti-submarine warfare frigates in partnership with Britain, following a competitive selection process that also involved bids from Germany, France, and the United States.

Norway plays a key role in NATO’s defence posture, monitoring a 2 million-square-kilometre stretch of the North Atlantic, an area frequently used by Russia’s northern fleet and nuclear submarines based on the Kola Peninsula.

The deal will eventually create a combined fleet of 13 frigates—eight British and at least five Norwegian—that will operate jointly in northern Europe. One of their main missions will be tracking and countering Russian submarine activity in the Arctic.

Norway, which shares a direct border with Russia, has been ramping up its defence spending amid Moscow’s war in Ukraine. The move also aligns with U.S. President Donald Trump’s calls for NATO allies to strengthen their own military capabilities.

This strategic partnership underscores a deepening UK-Norway alliance and highlights NATO’s growing focus on securing the Arctic and North Atlantic against Russian advances.