Declaring it a "very, very sad day" for himself and the nation, President Donald Trump has arrived in Las Vegas where a gunman killed 59 people at a concert.
He is meeting survivors and law enforcement officials in the aftermath of the worst mass shooting in modern US history.
Air Force One landed at the airport near the famed Las Vegas strip on a bright, sunny morning just days after a gunman on the 32nd floor of a hotel and casino opened fire on people at an outdoor country music festival below.
The Sunday night rampage killed at least 59 people and injured 527, some from gunfire and some from a chaotic escape.
I will be landing in Las Vegas shortly to pay my respects with @FLOTUS Melania. Everyone remains in our thoughts and prayers.— Donald J. Trump (@realDonaldTrump) October 4, 2017
"It's a very sad thing. We are going to pay our respects and to see the police who have done really a fantastic job in a very short time," Mr Trump told reporters before leaving the White House.
He said the authorities were "learning a lot more" about the gunman, Stephen Paddock, and that more details would be "announced at an appropriate time".
"It's a very, very sad day for me personally," he said.
The president's trip to Las Vegas follows his Tuesday visit to hurricane-ravaged Puerto Rico - a pair of back-to-back episodes that are testing his ability to unite and lift the US in times of strife.