U.S. President Donald Trump has called the bombing at a concert in the British city of Manchester "a barbaric and vicious attack upon our civilization" and told NATO allies he has new hope that nations can unite to defeat terrorism.
Trump was speaking at NATO headquarters on May 25, shortly after arriving in Brussels for his first meeting with NATO leaders since he took office in January.
He told British Prime Minister Theresa May that "all of the nations here today grieve with you and stand with you," calling for a moment's silence for the victims and families hit by the "savage attack."
“All people who cherish life must unite in finding, exposing, and removing these killers and extremists,” said Trump, who has repeatedly called on NATO to do more to combat terrorism.
In a statement issued by the White House, Trump said that leaks to the U.S. media of information from the investigation into the May 22 Manchester bombing are "deeply troubling" and a "grave threat to our national security."
The president said he was asking the Justice Department to lead an investigation into the matter, and "if appropriate, the culprit should be prosecuted."
British officials believe suspected suicide bomber Salman Abedi was part of a network and are hunting for accomplices who might have helped him build the bomb that killed 22 people, some of them children, and injured about 60.
Abedi's name was leaked to U.S. media just hours after the attack and pictures of the debris from the blast appearing to show bloodstained bomb fragments and the backpack used to transport the device appeared in The New York Times.
The leaks sparked an angry reaction from British officials, who said they undermined the inquiry and distressed families of the victims.
Upon arrival in Brussels, May, the British prime minister, said she would "make clear" to Trump that intelligence shared between the two countries must remain secure.
"These leaks were reprehensible, deeply distressing,” Lewis Lukens, U.S. charge d'affaires in London and acting ambassador to Britain, said on BBC radio on May 25. "We unequivocally condemn them."
"The United States government is launching an investigation into these leaks and will take appropriate action once we identify the source of the leaks," he added. "We are determined to identify these leaks and to stop them."
Earlier, the BBC reported, without citing a source, that police investigating the attack have stopped sharing information with the United States following the leaks.
Separately, the Associated Press quoted an unnamed British official as saying that the Manchester police will stop sharing bombing investigation information with the United States amid anger over the leaks.
There was no official confirmation of the reports from British authorities.
The extremist group Islamic State (IS) claimed responsibility for the attack, which was the deadliest in Britain since 56 people were killed in an attack on the London transport system in 2005.
Meanwhile, Manchester city police chief Ian Hopkins described the eight arrests made since the bombing as "significant" and items seized in raids as "very important."
Referring to the leaking of evidence from the investigation that appeared in The New York Times, Hopkins said it was "absolutely understandable" that this caused "much distress" to families of victims already suffering with their loss.
Queen Elizabeth visited victims at a children's hospital in Manchester, and a minute of silence was held in Britain on May 25 to remember the victims.
The minute of silence was held amid reports that a bomb disposal team was sent at a college in the Manchester suburbs after police responded to a call there. Police later indicated it was a false alarm, saying a suspicious package had been "deemed safe."