Incoming British Prime Minister Andy Burnham pledged on Thursday to find billions of pounds in his first budget to plug the "hole" in defence funding left by his predecessor, Politico reported.
Burnham said he would "take full responsibility" to fund the Defence Investment Plan announced earlier this week by outgoing Prime Minister Keir Starmer.
The Defence Investment Plan has allocated an extra £15 billion for the British armed forces, with no clarity on how it will be raised.
Burnham's promise will reassure British military commanders but will spark months of speculation about what tax increases, spending cuts or changes to borrowing rules Burnham could introduce to raise the funds in the next budget, expected in October or November.
In his first interview since winning a parliamentary by-election two weeks ago, Burnham, who is expected to become Prime Minister on July 20, confirmed reports that he had not been told about the spending gap.