Police officials said yesterday they are bracing for a neo-Nazi march and crowds of counter-demonstrators this afternoon and will flood the area around Pennsylvania Avenue NW and Lafayette Square with officers.

Police Chief Charles H. Ramsey said in an interview that 86 percent of all D.C. police would be on duty today to keep order. The American Nationalist Party, which also calls itself the Knights of Freedom, has received police and National Park Service permits to march down Pennsylvania Avenue and then rally across the street from the White House.

Officers' schedules were shifted so that police could put a maximum presence on the street. "We changed days off so we would minimize any overtime," Ramsey said.

An extra 1,450 officers will be stationed in the area between 15th and 22nd streets NW and F and K streets NW, said Executive Assistant Police Chief Terrance W. Gainer, who is coordinating D.C. police preparations.

"We have a number of officers who will be lining and guarding the parade route and Lafayette Park and nearly an equal number dispersed through businesses and hotels to make sure people remain calm," Gainer said. "By super-saturating this area, we hope to have a calming effect, so everybody can exercise their rights and not get nuts about it."

An ad hoc coalition called D.C. United to Stop the Nazis is planning to meet the neo-Nazi group at James Monroe Park, at 20th and I streets NW, the planned start of the march. Shalom International, a Florida-based Jewish activist group, is planning to meet the group at the march's terminus at Lafayette Square.

A coalition of civil rights groups, including the Latino Civil Rights Center, the American Jewish Committee and the NAACP, is planning a peaceful "respect rally" on the steps of the Lincoln Memorial. Cheryl Kravitz, director of the National Conference for Community and Justice of the national capital area, a rally sponsor, said that Del. Eleanor Holmes Norton (D-D.C.) will be the master of ceremonies of the event and that Mayor Anthony A. Williams is scheduled to speak.

The Jewish Defense League, a controversial activist group based in Los Angeles, announced yesterday its plans to join counter-demonstrators in confronting the neo-Nazi group. Bill Maniaci, a spokesman and security chief for the league, said the group was denied a Park Service permit to hold a counter-demonstration at Lafayette Square but said members planned to confront the neo-Nazi group anyway.

Maniaci said league members would try to impede directly the parade's route, as members did at two similar white-supremacist rallies in Coeur d'Alene, Idaho, earlier this month.

In a letter denying the Jewish Defense League's application, the National Park Service cited the crowds expected along the route of the parade.

"Due to the volatile views of the Knights, we anticipate potential violence from counter-demonstrations who intend to 'stop' the Knights demonstration," the Park Service wrote. "Indeed, violence has occurred at past white-supremacists' demonstrations. And at our meeting today, we appreciate your candor that in your efforts to stop the Knights, you may disobey police directions, disregard police barriers and occupy the park or streets reserved under permit to the Knights."

Rick Merryman, the Park Service's permit chief, said Lafayette Square would be closed from 6 a.m. today for security reasons.