Keir Starmer insisted Donald Trump is 'absolutely committed to the importance of Nato' today after the president raised doubts about the collective defence principle.
The PM played down alarm about whether US stands by Article 5 of the military alliance after Mr Trump said the meaning 'depends on your definition'.
Leaders are holding a tense gathering in the The Hague with fears over America distancing itself from the structure that has underpinned world peace since the Second World War.
They are due to sign off a new Nato target for defence spending to hit 3.5 per cent of GDP by 2035 - with another 1.5 per cent on related 'resilience' budgets.
However, some nations have signalled they do not view the level as a hard commitment, while there are questions about where the UK can find the extra £30billion.
