Queen Elizabeth II speaks to Amy Barlow, 12, from Rawtenstall, Lancashire, left, and her mother, Kathy, as she visits the Royal Manchester Children's Hospital on May 25, 2017. (Peter Byrne/Pool via AP)
Queen Elizabeth II speaks to Manchester bombing victim Evie Mills, 14, from Harrogate, and her father Craig, as she visits the Royal Manchester Children's Hospital on May 25, 2017. (Peter Byrne/Pool via AP)
Queen Elizabeth II speaks to Manchester bombing victim Millie Robson, 15, and her mother, Marie, as she visits the Royal Manchester Children's Hospital on May 25, 2017. (Peter Byrne/Pool via AP)
People gather ahead of a vigil in Albert Square, Manchester, England, Tuesday May 23, 2017. (Martin Rickett/PA via AP)
Britain's Prime Minister, Theresa May, writes a message at Manchester Town Hall in Manchester, England, Tuesday May 23, 2017. (Ben Birchall/Pool via AP)
A message is written on the pavement in Manchester, England, Tuesday May 23, 2017, the day after the suicide attack at an Ariana Grande concert . (Kirsty Wigglesworth/AP)
The Union flag flies at half mast outside the British Embassy in Paris, Tuesday, May 23, 2017. (Michel Euler/AP)
A couple embrace under a billboard in Manchester city centre, Tuesday May 23, 2017. (Kirsty Wigglesworth/AP)
Police block roads near to the Manchester Arena, seen at the right, in central Manchester, England Tuesday May 23, 2017. (Rui Vieira/AP Photo)
Fan leaves the Park Inn hotel in central Manchester, England, Tuesday, May 23, 2017. (Rui Vieira/AP Photo)
President Donald Trump makes a statement on the terrorist attack in Manchester after a meeting with Palestinian President Mahmoud Abbas, Tuesday, May 23, 2017. (Evan Vucci/AP Photo)
British Prime Minister Theresa May departs 10 Downing Street, London, to go to Manchester, Tuesday May 23, 2017. (Matt Dunham/AP Photo)
Police investigate on a bridge which links Victoria railway station to the Manchester Arena in central Manchester, England, Tuesday May 23 2017. (Rui Vieira/AP Photo)
Police block a road outside the Manchester Arena in central Manchester, England Tuesday May 23, 2017. (Rui Vieira/AP Photo)
A fan leaves with parents at the Park Inn hotel in central Manchester, England Tuesday May 23 2017. (Rui Vieira/AP Photo)
Forensic personnel stand on a bridge which links Victoria railway station to the Manchester Arena in central Manchester, Britain, Tuesday May 23 2017. (Rui Vieira/AP Photo)
Armed police patrol the streets near to Manchester Arena in central Manchester, England, Tuesday May 23, 2017. (Rui Vieira/AP Photo)
A fan is comforted as she leaves the Park Inn hotel in central Manchester, England, Tuesday May 23, 2017. (Rui Vieira/AP Photo)
Emergency services personnel speak to people outside Manchester Arena after reports of an explosion at the venue during an Ariana Grande concert in Manchester, England, (AP)
Nineteen people have died following reports of an explosion Monday night at an Ariana Grande concert in northern England, police said. (AP)
Police respond at Manchester Arena after reports of an explosion at the venue during an Ariana Grande gig in Manchester, England (AP)
Police respond at Manchester Arena after reports of an explosion at the venue during an Ariana Grande gig in Manchester, England (AP)
Police respond at Manchester Arena after reports of an explosion at the venue during an Ariana Grande gig in Manchester, England (AP)
Police respond at Manchester Arena after reports of an explosion at the venue during an Ariana Grande gig in Manchester, England (AP)
Police respond at Manchester Arena after reports of an explosion at the venue during an Ariana Grande gig in Manchester, England (AP)
Police respond at Manchester Arena after reports of an explosion at the venue during an Ariana Grande gig in Manchester, England (AP)
Armed police gather at Manchester Arena after reports of an explosion at the venue during an Ariana Grande gig in Manchester, England (PA via AP)