PRESIDENT Donald Trump has called the gunman who killed 59 people in Las Vegas a “very, very sick individual” and suggested he was ready to discuss gun laws “as time goes by”.

Trump was speaking to reporters yesterday as he departed for a trip to hurricane-ravaged Puerto Rico.

He called the gunman “demented” and said “we’re looking into him very seriously” and praised police in Las Vegas.

Trump stressed the shooting was a tragedy.

When asked, Trump declined to call the attack domestic terrorism.

Asked about US legislation, the president said “we’ll be talking about gun laws as time goes by”.

Stephen Craig Paddock, who killed 59 people and injured 527 others, was a big-spending gambler who took 23 guns into his hotel room before opening fire on crowds attending an outdoor music festival.

Paddock sprayed bullets on revellers enjoying the Route 91 Harvest Festival from the 32nd floor of the Mandalay Bay Hotel and Casino on Las Vegas Strip.

The 64-year-old retired accountant from Mesquite, Nevada, killed himself before officers stormed Room 135 in the gold-coloured glass skyscraper.

Assistant sheriff Todd Fasulo said Paddock had 23 guns, some with scopes, in his hotel room.

Authorities found 19 more guns at his home in Mesquite, as well as explosives and thousands of rounds of ammunition.

Several pounds of ammonium nitrate, a fertiliser that can be turned into explosives such as those used in the 1995 Oklahoma bombing, were discovered in his car.

Investigators believe the shooting, the most deadly in modern US history, was a “lone wolf” attack, and say they do not have any information to lead them to suspect there were more assailants.

Paddock’s brother described the gunman as a multi-millionaire property developer who liked to gamble large amounts of money at the world-famous casinos in Las Vegas who had no known political or religious agenda.

Eric Paddock told reporters his brother often received free rooms and meals from casinos, telling reporters: “He was a guy who had money.

“He went on cruises and gambled. We are completely dumbfounded. We can’t understand what happened.”

He also said their father was a bank robber who was once on the most wanted list.

Investigators are working to establish a motive for the attack, but a law enforcement official said there was no immediate indication that the massacre was connected to international terrorism.

Daesh claimed responsibility for the attack and said the gunman was “a soldier” who had converted to Islam months ago, but it provided no evidence to back up the claim.

Country music star Jason Aldean was performing on Sunday night at the end of the three-day festival in front of a crowd of more than 22,000 when the gunman opened fire from inside the 44-floor hotel across the street.

Paddock had checked into the hotel room on Thursday, authorities said.

People attending the country music concert described scenes of horror as they realised that what they first thought were fireworks were actually gunshots.

Harrowing video footage showed Aldean stopping his performance after an initial volley of shots could be heard.

After a pause, the gunman fired another volley, with the muzzle flashes visible from the casino as victims fell to the ground, while others fled in panic.

Jason Sorenson, of Newport Beach, California, said he first realised something was wrong when musicians left the stage.

He ran and said “we saw people with blood all over their shirts”.

Brandon Clack, of La Palma, California, said he heard many shots fired and the shooting that “went on for a long time, like 10 minutes”.

Concertgoers fled into casinos and crammed into cars to get away from the shooting.

Barbara Magro, of Orange County, California, said “they were getting into people’s trucks. I saw one with about 20 people in the back”.

Police shut down busy Las Vegas Boulevard, and federal and state authorities converged on the scene. Interstate 15 was briefly closed, and flights at McCarran International Airport were suspended.

Hospital emergency rooms were jammed with the wounded.

The dead included at least three off-duty police officers from various departments who were attending the concert, authorities said.