The European police agency is setting up a task force of more than 50 experts to help investigate non-Islamist threats in Scandinavian countries in the wake of the Norway attacks.
Soeren Pedersen said the group, based in The Hague, hoped to help Norway in the coming weeks and other countries such as Denmark, Finland and Sweden in assessing non-Islamist threats.
Norway has not yet requested forensic experts but Europol stood ready to assist, Mr Pedersen said.
"There is no doubt that the threat from Islamist terrorism is still valid," he said, adding that the task force could be expanded in the future to include even more European nations.
"But there have actually been warnings that (right-wing groups) are getting more professional, more aggressive in the way they attract others to their cause."
Since the September 11 terrorist attacks, European countries have viewed Islamic terrorism as the primary threat. But the fact that the suspect in Friday's attacks turned out to be a Norwegian with right-wing views is raising questions about whether home-grown, non-Islamic terror threats have been misjudged.
The alleged assailant was identified by Norway's national broadcaster as Anders Breivik, 32.
Authorities say he posted comments on Christian fundamentalist websites and held anti-Muslim views. He was also once a member of the youth wing of a right-leaning party.
In leaked diplomatic cables dating back to 2008, US diplomats warned that Norway seemed complacent about terror threats and criticised gaps in intelligence. The cables released by WikiLeaks also give a snapshot of simmering anti-immigrant and anti-Semitic tensions in Norway.
Anti-immigrant sentiment has grown in Norway as tensions rose over its policy of taking in conflict refugees.
In the 1990s, it welcomed immigrants from the Balkans. Years later, it opened its doors to large numbers of Iraqi refugees. The Norwegian government has said it expects some 15,000 new arrivals this year, many from Iraq, Afghanistan, Eritrea and Somalia.
Europe has seen an overall increase in xenophobia, boosting the ranks of ultra-nationalists and fuelling their activity. Still, experts and officials across Europe say the main terror threat hovering over the continent remains Islamic jihadism.
They suggest that the overall danger posed by European political extremists, both from left and right, is relatively small - but that anybody with the will and the means has a chance of wreaking devastation.
The numbers also indicate a low terror threat from ultra-rightists.
In a report earlier this year, Europol said there had been no right-wing terror attacks in Europe last year. But there were 45 left-wing and anarchist attacks in 2010 - a 12% increase from the previous year. There were also 160 separatist attacks last year, mainly in France and Spain.
The report said right-wing groups lacked cohesion and had little public support, though they were increasingly active on social networking sites.
"The numbers of right-wing extremist criminal offences are relatively low," said Europol, which has a large database where security data is regularly exchanged with partner countries and hosts a large counter-terrorism unit.
Interpol, the international police agency based in Lyon, France, covers 187 countries.
The task force would be a special group assigned to looking at non-Islamist threats and investigating links to right-wing networks through Europe.