WATCH: New York police in standoff with armed man at United Nations HQ

Heavily armed New York City police have arrested a man threatening to commit suicide with a shotgun outside the UN headquarters on East River, after a standoff that lasted nearly three hours.

The NYPD issued a traffic alert for the intersection of 42nd Street and 1st Avenue – right outside the UN HQ – on Thursday morning, and said the public should  “expect emergency vehicles in the surrounding area.”

A video posted on Twitter by Newsmax host Greg Kelly shows emergency vehicles blocking the road and SWAT personnel with long rifles standing by.

“Put down the firearm.  There are better ways to get your message across,” police can be heard telling the suspect, who appears to be a grey-haired white man, wearing a red sweater and a brown jacket.

It wasn’t clear from the video if the item in the man's hand is a gun, but Kelly’s video shows him holding on to something that appears to be a weapon. There was also a black bag of some kind on the ground by his feet.

At some point the suspect took off the jacket, and can be seen wearing the bright red sweater, as dozens of officers stand nearby.

Video from the scene showed the man holding what appeared to be a shotgun under his chin and speaking to officers. Police described him as being in his 60s and suicidal.

While the standoff was described as “ongoing” as of 12:30 on Thursday, the NYPD said there was “no threat to the public.” The UN has opened a different entrance to the HQ to the public. The main entrance on 1st Avenue remained closed, however.

About an hour later, the man handed a notebook to the police, who then delivered it to the UN staff inside the entrance, apparently at his request. 

He then dropped the shotgun and surrendered, around 1:40 pm local time. Photos from the scene show officers swarming around the man, who was handcuffed and taken into custody.