THE HAGUE/LONDON -- Britain will purchase 12 new F-35A fighter jets capable of carrying nuclear bombs to join NATO's nuclear mission, British Prime Minister Keir Starmer announced Wednesday.

Starmer made the announcement while attending a NATO summit in The Hague, Netherlands. NATO Secretary General Mark Rutte welcomed the decision, calling it "yet another robust British contribution to NATO".

Downing Street said in a statement on Tuesday that the purchase represents "the biggest strengthening of the UK's nuclear posture in a generation," and it reintroduces a nuclear role for the Royal Air Force for the first time since Britain retired its sovereign air-launched nuclear weapons following the end of the Cold War.

The jets will be deployed as part of NATO's nuclear Dual Capable Aircraft (DCA) mission, reinforcing the alliance's nuclear deterrence posture, the statement added.

The dual-capable aircraft, which can carry both nuclear and conventional weapons, will be based at RAF Marham in Norfolk.

Britain also published its National Security Strategy on Tuesday, warning that the country must "actively prepare" for the possibility of a "wartime scenario" on its own soil?— "the first time in many years" such a scenario has been considered, it said.

Separately, the British government announced Monday it would commit to spending 5 percent of GDP on defense by 2035, following intense diplomatic pressure from the United States and negotiations with allies.