It took a three-hour wait, but D.C. Mayor Marion Barry finally got an audience today with Liberian President William R. Tolbert, the new chairman of the Organization of African Unity.

It lasted less than 15 minutes.

Tolbert, who had just rushed in from his morning session in the conference chair, was polite in a soft-spoken way. The meeting was mainly a courtesy call.

Barry explained his early years in Washington with the self-help group Pride, Inc. Tolbert responded that the meeting of African heads of state is important "to bring about better conditions for Africans," especially economically.

Barry thanked him for the audience and introduced his party, attorney Robert B. Washington, chairman of the District Democratic Committee, and Courtland Cox, director of the District's Minority Business Opportunity Commission.

Tolbert suggested they all might "see something and let something interest you to make a life here."

"We have to increase the relationship between Africans and Afro-Americans," Barry said.

"That's what we must do in these days," Tolbert responded.

The brief meeting, was, however, a chance for some striking photographs. Seated on a red velvet sofa, before drapes of the same rich fabric, between the Liberian and OAU flags, Tolbert wore a white, gold-buttoned safari suit of a glistening cloth and white-feathered hat.

Around his neck hung a gold cross chain and on his collar, the red, white and blue stripes and single star of Liberia's flag. A many-carat diamond sparkled on his third finger and on the table in front of him rested his ebony swagger stick with its ends of carved ivory.

Yesterday, Monrovia Mayor Edward A. David hosted a buffet lunch for Barry and the city's council members in Monrovia's 20-year-old marble and glass city hall, and Barry told the group "It's good to be home."

Hearing familiar names in Liberia like Shaw and Johnson, the mayor said, made him feel like he was "back in Washington at 14th and U."

Then, in a ringing speech reminiscent of his campaign oratory last year, Barry waxed more eloquent than he has so far on his trip.

"The people of Africa," he said "have to be admired." "It's sometimes easy to do well when you have the resources." he said, but in Africa he has seen evidence of progress where resources are meager.

After praising the "tenacity, courage, guts and faith of Africans" Barry closed his sermon-like address with a quotation from poet James Weldon Johnson's Negro national anthem: "Facing the rising sun, a new day is begun. Let us march on till victory is won."

Barry reminisced that he had met David in Washington when David was a student at Howard University and neither of them dreamed that they would become the mayors of their nation's capitals.

David toasted Barry, calling him "one of the most outstanding black citizens of the U.S.," and he gave Barry a gold key to the city of Monrovia. In casual conversation today he informed Barry that it was "solid gold" and worth "over $500." Barry joked that he would have it "melted down."

This is the second of five African capitals Barry is to visit on this trip. So far Washington has acquired two potential "sister" cities: Dakar, the capital of Senegal, and now Monrovia.

"Washington is big enough to have two sisters," Barry said. "We have the resources and the people." He said the details of the sisterhood would be worked out in the fall.

Barry has been escorted around Liberia by the U.S. International Communication Agency, the city of Monrovia, the Liberian government and escorts for the Organization of African Unity.