A man who claimed to be a researcher seeking "a private audience" with Donald Trump spent three hours scaling the glass facade of Trump Tower using large suction cups before officers hauled him to safety through an open window.

The climber wore a backpack and used a harness and rope stirrups to fasten himself to the side of the 68-story Manhattan skyscraper on Wednesday. He climbed as high as the 21st floor before officers grabbed him.

Police identified him as a 20-year-old Virginia man and said he was taken to a hospital for evaluation.