He said that once information from hostages and the suspect suggested "further loss of life was imminent," a decision was taken for SWAT to breach the wall of the club.
Mateen was armed with an assault-style weapon and a pistol. A third weapon was found in his car, authorities said. Law enforcement sources earlier told NBC News that Mateen swore allegiance to the leader of ISIS in a 911 call moments before the rampage at Pulse.
However, law enforcement officials have said there was not yet any indication Mateen was in touch with terrorists overseas or that the attack was directed by anyone else.
Florida Gov. Rick Scott confirmed he had asked President Barack Obama to declare a state of emergency in wake of the shooting.
“In the face of hate and violence, we will love one another,” Mr. Obama said in a special address from the White House. “We will not give in to fear or turn against each other. Instead, we will stand united as Americans to protect our people and defend our nation, and to take action against those who threaten us.”
A full list of names of victims still pending.