Theresa May is to raise concerns with Donald Trump after evidence from the Manchester Arena bombing was apparently leaked to US media.
According to a BBC report, UK officials were “furious” when photos appearing to show debris from the attack appeared in the New York Times.
Monday night’s attack at Manchester Arena killed 22 people – including children – and injured 64.
Eight men are now in custody following the attack, carried out by suicide bomber Salman Abedi.
The prime minister is expected to raise the issue of the leak with the US president when they meet at a Nato summit later.
Details about Abedi’s identity had already emerged in the US media less than 24 hours after the explosion and against the UK’s wishes.
Home Secretary Amber Rudd said she was “irritated” by the disclosure of Abedi’s identity and had warned Washington “it should not happen again”.
However, the pictures of debris – which appear to show bloodstained fragments from the bomb and the backpack used to conceal it – were subsequently leaked to the New York Times, prompting a furious response from within Whitehall and from UK police chiefs.
BBC security correspondent Gordon Corera says UK officials believe that US law enforcement rather than the White House is the likely culprit for the leaks.