The commitment came as NATO countries face pressure to raise defence spending in the face of global threats, particularly from Russia.

"In a world that is the most dangerous it has been since the end of the Cold War, we cannot be complacent," Sunak told reporters in Warsaw, where he held a press conference with NATO Secretary-General Jens Stoltenberg.

The increase in spending from 2.3 percent will see the UK become one of the highest spenders on defence in the 32-member defence alliance after the United States, the British government said.

It means the UK is expected to spend pound87 billion on defence in 2030-31, an increase of pound23 billion over current levels.

"I believe we must do more to defend our country, our interests, and our values," Sunak said, announcing "the biggest strengthening of national defence for a generation".

Western nations are under pressure to boost defence funding following Moscow's invasion of its neighbour Ukraine as well as the threat of escalation in the Middle East.

EU chief Ursula von der Leyen recently called for a "European awakening on defence and security".

Brussels is set to come up with more proposals for financing the defence push by a summit of EU leaders in June.

Sunak has also faced calls from his Conservative Party to boost defence spending, with some calling for a level of three percent of GDP.

On Tuesday, Sunak also announced pound500 million additional funding for Ukraine's war effort against Russia.