WASHINGTON — Representative Steve Scalise of Louisiana, the No. 3 Republican in the House, addressed a group of white supremacists and neo-Nazis in 2002, a Scalise spokeswoman confirmed Monday as his party prepared to take control of both chambers of Congress.

Mr. Scalise made his remarks to the European-American Unity and Rights Organization, which was founded two years earlier by David Duke, the former Ku Klux Klan leader and Louisiana politician. Mr. Scalise was a Louisiana state legislator at the time.

The Southern Poverty Law Center has described the organization — which uses EURO as an acronym — as a hate group, while noting that in recent years it has “accomplished little” and serves “primarily as a vehicle to publicize Duke’s writing and sell his books.”

Moira Bagley Smith, a Scalise spokeswoman, said the congressman “has never been affiliated with the abhorrent group in question.”