Washington, Jun 14 (IANS): The White House on Monday said President Barack Obama will visit Orlando city in Florida on Thursday to mourn the victims killed at the gay nightclub.

"On Thursday, the president will travel to Orlando to pay his respects to victims' families, and stand in solidarity with the community as they embark on their recovery," Xinhua news agency cited a White House statement as saying.

Obama's trip will come four days after a lone wolf gunman shot dead 49 people and injured 53 at the Pulse gay nightclub in Orlando, making it the deadliest mass shooting in the US history and worst terror strike after the 9/11 attacks in 2001.

Afghan-origin Omar Mateen, 29, of Port St. Lucie in Florida, opened fire around 2.00 a.m. on Sunday. He was killed after a shootout with police.

After his meeting with Director of Federal Bureau of Investigation James Comey on Monday, Obama said the Florida shooting was "homegrown extremism".

"As far as we can tell right now, this is certainly an example of the kind of homegrown extremism that all of us have been so concerned about for a very long time," said Obama at the White House.

According to Obama, so far there was no "clear evidence" that the gunman had been directed externally.

"It does appear that at the last minute, he announced allegiance to IS," said Obama. "But there's no evidence so far that he was, in fact, directed by IS."

IS-linked news agency Amaq on Sunday said the Islamic State militant group was responsible for the shooting.