Police were forced to use a stun gun to subdue a knife-wielding man who attempted to enter Parliament House in Canberra today.

ACT Police and AFP Protection Service officers rushed to Parliament House about 1pm after people reported seeing a man walking towards the building with a knife.

Officers attempted to negotiate with the man but things quickly escalated and an officer deployed his stun gun.

The man has now been taken into custody.

“There were no national security concerns regarding this incident,” an AFP spokesman said.

Parliament House in Canberra went into lockdown while the threat remained. (9NEWS) (9NEWS)

The man reportedly tried to enter the Ministerial wing of Parliament House in Canberra. (9NEWS) (9NEWS)

Justice Minister Michael Keenan thanked the AFP for their response to the incident.

“I would like to acknowledge the swift and professional actions of Australian Federal Police outside the Ministerial Wing of Parliament House in Canberra today,” he said in a statement.

“Officers attended to a man who was observed to be armed with a knife. The man was tasered as he failed to relinquish the knife.

“There were no national security concerns regarding this incident. No one was injured.

“Our security agencies are the best in the world, and they are working every day to keep Australia safe.

“Parliament House continues to be a safe place to visit during the school holidays.”

Australian Federal Police closed the road surrounding Parliament House while the threat remained. (9NEWS) (9NEWS)

9NEWS footage shows police arresting the man outside Parliament House.

What appears to be a common kitchen knife can be seen on the ground close to the man as police handcuff him.

The man was seen being led into a waiting police wagon.

Police blocked off access to Parliament House after the alarm was raised and stopped all access to and from the building as they searched for the armed man.