Police were called to the skatepark about 1am on Sunday and found the man and a 16-year-old boy with stab wounds. Both were treated by paramedics but the 18-year-old died at the scene.

Community members have expressed concerns about safety and called for a greater police presence in Weston Creek. Mr Barr said he understood those concerns and that ACT police had deployed more patrols in light of the incident.

"There are more police on patrol and in light of the circumstances around this particular case and the broader concerns, ACT Policing will be in a position to respond to those concerns," Mr Barr said.

Mr Barr said police had faced challenges as they had to supervise quarantine arrangements from international visitors and domestic residents returning from Victoria. He hoped with fewer cases in Victoria there would be fewer people quarantining and that would free resources.

"We would hope that with fewer people in quarantine in the weeks ahead that will take a bit of pressure off both ACT Health and ACT Policing as it relates to supervising that program," he said.

Mr Barr also expressed his condolences for the victim's family.

"Our hearts go out to their family and friends," he said.

More to come.