Republican Donald Trump has said he would like people on terror watch lists to be prevented from buying guns, in the wake of the Orlando shootings.

The presumptive presidential nominee tweeted that he would meet the National Rifle Association to discuss the issue.

Forty-nine people were killed in a gay nightclub by Omar Mateen, who had been put on a terror watch list by the FBI.

His wife is also being questioned in connection with the atrocity, the worst mass shooting in modern US history.

Up to now, Trump has been a strong supporter of protecting gun rights and his candidacy was endorsed by the NRA, a powerful gun lobby, last month.

But on Wednesday, he tweeted: "I will be meeting with the NRA, who has endorsed me, about not allowing people on the terrorist watch list, or the no fly list, to buy guns."

The FBI has two terror "watch lists". The smaller one bans flying to and from the US and there is also a larger one, which Mateen was on.

 Trump made a similar point in a television interview last November but had not mentioned it since the recent attacks.

Mateen was put on the list for 10 months while under investigation following inflammatory comments at work.

But the FBI concluded there was no evidence he was a terror threat.

The 29-year-old, a US national with Afghan parents, bought an assault rifle and a handgun in early June.

Investigators are still unclear of the motive for the attack.

Mateen pledged allegiance to so-called Islamic State as he carried out the attack and people who knew him said he displayed an apparent hatred towards gay people.

The FBI is also investigating reports that Mateen made several visits to the Pulse nightclub and made contact with other men on gay dating apps.

His father said on Wednesday that he blames his son's actions on the influence of "horrible killer group" Islamic State. He also said the club should have had stronger security.

Supporters of tougher gun laws, like President Barack Obama, have said the attack in Orlando strengthens their cause.

The president, and several leading Republicans, have attacked Trump for renewing his call to ban foreign Muslims from entering the US.