Washington: The US President Barack Obama on Sunday said the "horrific" mass shooting at a nightclub in Orlando, Florida, that killed 50 people, is an act of "terror" and an "act of hate", as he reminded the countrymen of the easy access to firearms people enjoy in America.
"This was an act of terror, and an act of hate," Obama said, adding that the Federal Bureau of Investigation is investigating this as an act of terror.
However, nothing is definitively known about the motivation behind this mass shooting, he told reporters at the White House this afternoon.
"This is a heart breaking day for gays and lesbian's community," a grim looking Obama said.
"Today marks the deadliest shooting in American history," he added.
In the wee hours of Sunday morning at a gay nightclub in Orlando, a lone gunman ? identified as Omar Siddique Muteen, who came to the US from Afghanistan -- killed 50 people and injured 53 others.
This was the 15th time that Obama has come out to address the nation after a mass shooting.
"This is the deadliest shooting in the American history," Obama said, adding that this is further reminder of how someone can easily get fire arms for such violence.
Americans have to decide if having easy access to firearms is "the kind of country we want to be," he said.
"We will not give into fear," Obama asserted, and assured the nation that he would take action against those responsible for this.
The President came into the briefing room soon after having met with the FBI Director and Secretary of Homeland Security.
A State of emergency has been declared in Florida. The Florida Governor, Rick Scott, has also declared the overnight mass shooting as an act of terrorism.
The US President, however, did not mention Islam or Islamic terrorism, as being blamed by some of his political opponents.
In an interview to CNN, Congressman Peter King alleged that the gunman was radicalised and an supporter of Islamic State.
Quoting unnamed law enforcement official CBS said Muteen pledged loyalty to ISIS in a 9/11 call before the shooting. He was also under FBI investigation for some time.
His father Mir Siddique has apologised for mass shooting while stressing that the incident has nothing to do with religion.
"We are saying we are apologising for the whole incident. We weren't aware of any action he is taking. We are in shock like the whole country," he told NBC news channel.
"This had nothing to do with religion," he added.
The Republican presidential presumptive nominee, Donald Trump, condemned the horrific incident in Florida.
"Appreciate the congrats for being right on radical Islamic terrorism, I don't want congrats, I want toughness and vigilance. We must be smart!" he tweeted.
"Woke up to hear the devastating news from FL. As we wait for more information, my thoughts are with those affected by this horrific act," said the presumptive Democratic presidential nominee, Hillary Clinton.
In a proclamation, the US President ordered that the national flags at all military posts and naval stations, be flown at half-staff.
Obama said this is a mark of respect for the victims of the act of hatred and terror perpetrated in Orlando, Florida.
"Although, it's still early in the investigation, we know enough to say that this was an act of terror and an act of hate. And as Americans, we are united in grief, in outrage, and in resolve to defend our people," Obama said in his remarks.
He said investigating agencies are still learning all the facts.
"This is an open investigation. We've reached no definitive judgement on the precise motivations of the killer. The FBI is appropriately investigating this as an act of terrorism," he said.
"And I've directed that we must spare no effort to determine what -- if any -- inspiration or association this killer may have had with terrorist groups. What is clear is that he was a person filled with hatred. Over the coming days, we'll uncover why and how this happened, and we will go wherever the facts lead us," he said.
Obama said this is an especially heartbreaking day for all fellow Americans -- who are lesbian, gay, bisexual or transgender.
"The shooter targeted a nightclub where people came together to be with friends, to dance and to sing, and to live. The place where they were attacked is more than a nightclub -- it is a place of solidarity and empowerment where people have come together to raise awareness, to speak their minds, and to advocate for their civil rights," he said.
This is a sobering reminder that attacks on any American -- regardless of race, ethnicity, religion or sexual orientation -- is an attack on all and on the fundamental values of equality and dignity that define as a country, he said.
"And no act of hate or terror will ever change who we are or the values that make us Americans," he asserted.
"This massacre is therefore a further reminder of how easy it is for someone to get their hands on a weapon that lets them shoot people in a school, or in a house of worship, or a movie theatre, or in a nightclub. And we have to decide if that's the kind of country we want to be. And to actively do nothing is a decision as well," the US President said.