Her remarks came after the group the Nordic Resistance Movement (Den nordiske motstandsbevegelsen- DNM) held a demonstration in Kristiansand on Saturday.
“We must ensure that the organization, which primarily comes from a Swedish background, does not get a foothold in Norway and that they do not recruit Norwegian youth," the PM told TV2.
Solberg ended an election campaign in southern and western Norway on Tuesday with a visit to Kristiansand, where up to 70 right-wing extremists marched through the city's streets without seeking the proper permits from local officials.
Police were on hand in large numbers during the march but, apart from kicking a few people out, officers did not intervene to stop the unsanctioned demonstration.
The police have come under criticism for failing to act, but have defended their response and said that they handled the demonstration properly.
Solberg declined to join in on the criticism, saying that it was up to the police to determine the best way to react to the DNM's presence.
She added however that right-wing extremists must be confronted.
"We have made an action plan to combat extremism, and it also covers this kind of extremism," Solberg said.
Saturday's demonstration by the DNM was originally supposed to take place in the town of Fredikstad, but police there blocked the planned action and the 60-70 members of the group converged instead upon downtown Kristiansand.
Following the demonstration, 18 Swedish members of the extremist group were stopped at the border and expelled from Norway by the Eastern Police District.
Extremists from Finland were also part of the group that marched through Kristiansand, police said.
The Nordic Resistance Movement members were greatly outnumbered by the roughly 300 Norwegians who turned out for a counter-protest to let the neo-Nazis know they were not welcome.