A man brandishing a shotgun surrendered to police after a two and half hours standoff outside the UN headquarters in New York on Thursday.

Law enforcement sources said the man showed up outside the UN building at the corner of 42nd street and 1st avenue at about 11:15 a.m., holding a shotgun under his chin.

During much of the standoff, the yet-to-be identified individual paced back and forth near the entrance while holding a shotgun.

Police closed off nearby streets as a result of the situation, which prompted a massive police response.

Dozens of police vehicles and ambulances, and heavily armed policemen were seen by Xinhua reporters at the scene.

According to a UN spokesperson, UN Secretary-General Antonio Guterres was brought to a safe location during the lockdown.

Just after 1 p.m., the gunman produced a pile of documents and apparently demanded that they be delivered to the UN. The content of the documents is not yet known.

At approximately 1:40 p.m., police retrieved the documents and handed them over to headquarters personnel.

The man was then handcuffed and escorted into an ambulance.

At 1:55 p.m., the UN said that the police activity had been resolved and all UN headquarters occupants were advised to resume their normal functions.

No UN staff or associates were in danger, the UN said earlier.