D.C. Police Chief Isaac Fulwood Jr. said last night his officers will help the U.S. Park Police keep order on the Mall if a federal judge chooses that route for a Ku Klux Klan march scheduled for Sunday.

Fulwood's statement came three days after Park Police Chief Lynn Herring said he was calling on federal agencies to help him because his 500 officers could not handle the march alone and D.C. police had refused to directly help him.

It is still not certain where the Christian Knights of the Ku Klux Klan of Mount Holly, N.C., will march, or if there will be a march Sunday. U.S. District Court Judge Louis F. Oberdorfer is to hold a hearing today on a request for a court order demanding that the Klan members be allowed to march and that the D.C. police protect them from counterdemonstrators.

Fulwood, speaking on the subject for the first time this week, said he believes federal and city police are united in their assignment to ensure public safety.

"If we sent the wrong message, and I hope we haven't, I want to make it clear now that we will support the Park Police wherever they need us," he said.

Yesterday, Herring affirmed his earlier statements that D.C. police said they would only be available as a strike force to help in an emergency during the march. He said he could not recall a time when D.C. police had refused to assign officers to work with his force.

"It was like a broken record," he said. "We would ask and they would say no. I didn't make a formal request for assistance because when they said 'no assistance,' then why should I ask for a specific number of officers? It would have been embarrassing."

On Tuesday, the Washington legal director of the American Civil Liberties Union, Arthur Spitzer, filed suit against Fulwood, the mayor, the city and the federal government to force approval of a permit for the Klan to march an 11-block route on Constitution Avenue NW. The city has approved a four-block march from Seventh Street to Third Street NW on Constitution Avenue.

Spitzer said if the judge did not rule in favor of the longer city street route, then his second request was for approval of a permit by the National Park Service for a march on Madison Drive on the Mall. From the Mall, the marchers would enter the four-block stretch they have D.C. police permission to use.

Wherever the Klan marches, Sahu Barron, an organizer for the radical leftist coalition called the All Peoples Congress, has promised that thousands of demonstrators will be ready to try to stop the Klan.

However, she said she is waiting for approval of several permits she has requested from the National Park Service and the D.C. police. One application is for permission to march on Constitution Avenue before or after the Klan.

The controversy this week over how District and Park police would handle the march and counterdemonstrations was unusual because the agencies have a long-standing history of cooperation, according to Herring and Fulwood.

The cost of the police detail was one of the factors that Fulwood cited in a letter to Spitzer Tuesday when he said he had approved a permit for a four-block march.