DONALD Trump said it was a “very, very sad day” for himself and the US as he met survivors in Las Vegas days after a gunman killed 59 people at a concert.

Air Force One landed at the airport near the famed Las Vegas strip in the aftermath of the worst mass shooting in modern US history in which 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.

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“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 visit came as Paddock’s girlfriend was being quizzed by police attempting to find out why a man with no record of violence or crime would open fire on a concert crowd from a high-rise hotel.

Marilou Danley, 62, who was in the Philippines at the time of the shooting, was met by FBI agents after she touched down in Los Angeles on Tuesday night.

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Sheriff Joseph Lombardo, who has called Ms Danley a “person of interest” in the attack, said: “We anticipate some information from her shortly.”

He said he is “absolutely” confident authorities will find out what set off Paddock, a 64-year-old high-stakes gambler and retired accountant who killed himself before police stormed his 32nd-floor room at the Mandalay Bay Hotel and Casino.

Ms Danley first arrived in the Philippines on September 15, according to immigration documents.

She departed on September 22 then returned three days later on a flight from Hong Kong. She was travelling on an Australian passport.

Ms Danley’s Australia-based sisters believe Paddock sent her away to prevent her from interfering with his plans.

One of the women said Ms Danley is “a good person” who would have stopped Paddock had she been there.

Another of the sisters, who live near Brisbane, Queensland, said they believed Marilou knew Paddock had guns, but not as many as he had.

Paddock transferred 100,000 dollars (£75,000) to the Philippines in the days before the shooting, a US official said.

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Investigators are still trying to trace that money and looking into a least a dozen financial reports over the past several weeks that showed Paddock gambled more than 10,000 dollars (£7,500) per day, the official said.

Mr Trump, who ran his presidential campaign with the backing of the National Rifle Association, earlier appeared somewhat open to having a debate on guns, but not soon.

“At some point, perhaps, that will come,” he told reporters. “But that’s not for now.”