A 20-year-old Donald Trump supporter who scaled the Trump Tower in Midtown Manhattan for three hours using suction cups and a climbing harness was pulled inside through a window by police who had tried to coax him into the building.

The man reached the 21st floor of the 58-story tower on Fifth Avenue which is headquarters for the U.S. Republican presidential nominee's election campaign.

Police removed large window panels above him and several officers, some wearing helmets, stood at the windows. The climber shifted his route several times.

At a news conference, the New York Police Department said the unidentified man did not express a desire to harm anyone and said his mission was to get a meeting with Trump.

The man was undergoing psychiatric evaluation and would be arrested, police said.

In a video that was uploaded to YouTube, the man discussed climbing the tower in a message addressed to Trump.

He referred to himself as an "independent researcher" seeking a private audience with Trump to discuss an unspecified important matter.

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