A Lockheed Martin F-35A fighter jet performs during an exhibition flight at the 55th International Paris Airshow at Le Bourget Airport near Paris, France, 16 June 2025; Credit: REUTERS/Benoit Tessier/File Photo

THE HAGUE (Reuters) - The United Kingdom said it would buy a dozen F-35A fighter jets capable of firing tactical nuclear weapons in what it described as the biggest expansion of its nuclear deterrent in a generation.

The purchase of the Lockheed Martin jets would allow Britain's air force to carry nuclear weapons for the first time since the end of the Cold War, Downing Street said.

"In an era of radical uncertainty we can no longer take peace for granted," Prime Minister Keir Starmer said in a statement.

The United Kingdom's nuclear deterrent is currently limited to the continuous deployment of at least one nuclear-armed submarine patrolling at sea.

Starmer's government is increasing defence spending and upgrading its military forces, including its submarine fleet, as it faces increasing hostility from Russia and as the United States retrenches from its traditional role as a defender of Europe.

The announcement by the UK on expanding its nuclear deterrence was made at a NATO summit in The Hague where European members are set to agree an ambitious new target to spend 5% of national income on defence and security.

The US will supply B61 tactical nuclear weapons for use on the planes as part of a plan for UK to take on more responsibility for European security, said a British official who declined to be named.

Britain said the purchase of the jets would allow it to contribute so-called dual-capable aircraft to NATO to carry nuclear weapons in the event of a conflict.

NATO Secretary General Mark Rutte said "this is yet another robust British contribution to NATO".

New capability

The cost of each F-35A jet is about 80 million pounds ($109 million), putting the total bill for the twelve planes at just under one billion pounds, according to another British official, who asked not to be named.

UK's nuclear deterrent currently rests solely on the Trident submarine-based system, which misfired during a test last year, the second successive test failure after one veered off course in 2016.

The last time UK possessed an independent air-launched nuclear capability was in 1998 when the WE-177 free fall bomb was withdrawn from service, according to the UK parliament.

Tactical nuclear weapons are intended for battlefield use, as opposed to strategic weapons designed to be fired across vast distances.

By purchasing the F-35A fighter jets, the United Kingdom would be able to diversify its military options and align more closely with NATO allies such as France and the United States, which maintains land, sea and air-based nuclear capabilities.

The United States withdrew its last nuclear weapons from UK in 2008, in a sign at that time that the threat of conflict following the end of the Cold War was receding.

Downing Street said buying the new jets would support about 20,000 jobs in the UK and underline its commitment to NATO.

The government has pledged to boost overall defence and security spending to 5% of economic output by 2035 to meet a NATO target and said on Tuesday 24 June 2025 it must "actively prepare" for war at home for the first time in years.