Merseyside Police surrounded an office building in the city centre and closed a number of streets during the standoff.
"Merseyside Police is dealing with a security alert at a business premises in Silkhouse Court, Tithebarn Street, Liverpool. Officers were called to the scene following reports of a man acting suspiciously and claiming to be in possession of a suspect package," a police statement said.
Staff in the building, reportedly a solicitors' office, earlier tweeted about a "bomb scare on the fifth floor" and then evacuated the building.
Police negotiators are trying to speak to the man, while a bomb disposal team remains on standby at the scene.
