Britain will be “the leading European nation” in Nato under a Labour government, the new defence secretary, John Healey, pledged in an interview at the Nato summit in Washington DC – though spending may have to rise significantly if the UK is to remain ahead of Germany.

The cabinet minister, appointed last Friday, acknowledged that European countries within Nato would have to take on more of the burden of defending the west against Russia – regardless of whether Joe Biden or Donald Trump won the US presidential election in November.

“Whoever is elected to the White House, we have to recognise that American priorities are likely to shift to the Indo-Pacific,” Healey said at the Nato summit in Washington, suggesting that the US will inevitably redirect its military focus to China.

“The consequences of that are that European nations in Nato must do more of the heavy lifting and some of the leadership that traditionally we have been able to look to the Americans to do.

“So Keir Starmer’s commitment during this summit, [is] that under the new government, Britain will be the leading European nation in Nato,” Healey said. “We recognise the responsibilities that with other European nations we must pick up.”

Labour has promised to increase defence spending to 2.5% of GDP from its existing level of 2.32% but it has not said when it will do this. On Wednesday, Healey said a review of budgets would part of a strategic review that would be launched next week by the prime minister.

The new defence secretary promised that the review would take place “in less than a year” and in such a way that “we can get to grips with difficult decisions that need to be taken early”.

Britain has traditionally been the leading European nation in Nato, as measured by defence expenditure, outspending Germany and France. But since Russia’s invasion of Ukraine, Germany’s chancellor, Olaf Scholz, has led a dramatic change in policy.

Figures released by Nato showed that in dollar terms the UK spent $77bn (£60bn) in 2023 compared with $73.1bn for Germany and $59.3bn for France. But, next year, Germany’s budgets are expected to soar past Britain at $97.7bn – compared with $82.1bn for the UK.

Before the summit, Downing Street said Starmer would use his trip – his first international engagement after becoming prime minister last Friday – to call on Nato countries to increase defence spending further. The intention, a spokesperson said, was to send “a strong signal” to Russia as it continues to attack Ukraine.

European Nato allies have principally worried about the impact of a fresh Donald Trump presidency. The Republican challenger to Biden threatened to leave the alliance in 2018 when he was last president, and has threatened that any member spending less than 2% of GDP on defence would not be protected by the US.