An 18-year-old Pearce man has been charged with sexually assaulting a teenage girl following a house party in Molonglo over the weekend.

Police allege the man attended a party on Friday night before leaving with a girl known to him and walking to a nearby park.

While at the park, the man allegedly engaged in a series of unwanted and non-consensual acts despite the girl repeatedly telling him to stop.

The incident was reported to police the following day and an investigation began.

Police arrested the man at home on Tuesday. He has been charged with six counts of acts of indecency without consent and one count of act of indecency third degree.