The young man was arrested outside Parliament on Monday night and appeared in an ACT court on Tuesday morning.

He is accused off possessing an offensive weapon with intent and recklessly threatening to kill a person.

The man is expected to undergo a mental health assessment before he will be able to apply for bail.

The Department of Parliamentary Services insists there is no apparent ongoing threat but says security will be increased on sitting nights.

"For the peace of mind of all building occupants we have immediately engaged private security contractors to conduct patrols," the department said.

Security guards will patrol a car park next to the ministerial wing, where government ministers and their staff enter and exit, as well as a second cark park used by other people who work at parliament.

"Please be assured the safety of everyone who works in Australian Parliament House is paramount," the department said.

"We will be working with the National Capital Authority to review public safety requirements and any additional long-term measures."

Australian Associated Press