“Police investigating the Manchester Arena bomb attack have stopped sharing information with the US after leaks to the media.
UK officials were outraged when photos appearing to show debris from the attack appeared in the New York Times.
It came after the name of bomber Salman Abedi was leaked to US media just hours after the attack, which left 22 dead.
Theresa May said she would tell Donald Trump at a Nato meeting that shared intelligence “must remain secure”.
The US’s acting ambassador to the UK “unequivocally condemned” the leaks in a BBC radio interview.
“These leaks were reprehensible, deeply distressing,” Lewis Lukens said.
“We have had communications at the highest level of our government … we are determined to identify these leaks and to stop them.””