Obama to pay respects to Orlando massacre victims

White House says president to visit city to 'stand in solidarity with the community as they embark on their recovery'

President Barack Obama will travel to Orlando on Thursday to pay his respects to the families of those massacred at a gay nightclub, according to the White House.

Spokesman Josh Earnest said in a statement issued Monday that Obama will "stand in solidarity with the community as they embark on their recovery".

Omar Mateen opened fire at the Pulse nightclub early Sunday, killing 49 people and wounding 53 others before dying in a shootout with police.

His motives remain unclear.

FBI Director James Comey said Mateen had previously claimed membership with Hezbollah, a fierce enemy to Daesh, which in turn is the terrorist group the shooter declared allegiance to during a 911 call while the attack was in progress.

Comey said Mateen also cited Abu Salha, an American suicide bomber who killed himself in Syria for al-Nusra Front, another anti-Daesh group. He also referenced the Tsarnaev brothers who carried out the Boston Marathon bombings in 2013. Tamerlan and Dzkhokhar Tsarnaev had no known links to terror groups.

The FBI chief did make a point, however, of saying that the agency was "highly confident that this killer was radicalized and at least in some part through the Internet".

Mateen's ex-wife, Sitora Yusufiy, described Mateen as being abusive and "unstable and mentally ill".

The massacre is considered the deadliest mass shooting in U.S. history.

The Orlando Regional Medical Center said in a statement to The Associated Press that 29 victims are still hospitalized, with many still critically ill or in shock.