HELSINKI (AP) — Norwegian authorities have arrested a high-profile U.S. white supremacist scheduled to speak at an international far-right conference in Oslo and say they will seek his deportation.

Spokesman Martin Bernsen from Norway's domestic security agency PST told Norwegian public broadcaster NRK that a U.S. citizen was arrested Saturday "on the basis of the Immigration Act section 106" including a suspicion that "he may play an obvious role in radicalization."

PST didn't give the person's name, but he was identified by Norwegian media as Greg Johnson who was a scheduled speaker in the conference by the Scandza Forum, a far-right network known for its anti-Semitic and racist views.

Based in Seattle, Washington, Johnson is a writer and editor-in-chief of the white nationalist Counter-Currents Publishing and a contributor to several publications.