British foreign minister David Cameron urged fellow NATO members on Thursday to meet pledges to spend 2% of GDP on defence, saying a tougher foreign policy is needed in a world more dangerous "than most of us have ever known".

In a wide-ranging speech that touched on his 2010-16 time as prime minister, Cameron said the West was being tested by Iran, Russia and China among others and nations must show courage or allow "our adversaries (to)...write our future for us".

With a six-point plan, Cameron, who was brought back into government by Prime Minister Rishi Sunak in November, said Britain must prioritise security, be bolder, harder-edged, realistic and ruthlessly practical.

"We are in a battle of wills. We all must prove our adversaries wrong – Britain, and our allies and partners around the world," Cameron told an audience at the UK's National Cyber Security Centre.

"The upcoming NATO summit must see all allies on track to deliver their pledge made in Wales in 2014 to get to that 2%. And we then need to move quickly to establish 2.5% as the new benchmark for all NATO allies."

He hailed Sunak's promise to boost British defence spending to 2.5% of GDP by 2030 - amounting to an additional 75 billion pounds ($94 billion) over the next six years - and said it was vital to prioritise security against China, Russia and Iran.

On Israel's war against Hamas in Gaza, Cameron said Britain should be practical and focus on a humanitarian pause in the fighting, rather than a call for an immediate ceasefire that "makes it no more likely".

He also drew a distinction in scale and procedure between British and U.S. arms exports to Israel when asked if London would withhold weapons deliveries, following U.S. President Joe Biden's vow to do so if Israeli forces storm southern Gaza's Rafah, which is packed with vulnerable displaced people

On Russia, Cameron said nations were not learning the lessons of President Vladimir Putin's full-scale invasion of Ukraine two years ago.

"If Putin's illegal invasion teaches us anything, it must be that doing too little, too late only spurs an aggressor on. This cannot go on. We need to be tougher and more assertive." ($1 = 0.8006 pounds)

(Reporting by Michael Holden and Elizabeth Piper; editing by Kevin Liffey and Mark Heinrich)