"Don't expect him to be on time. He is so human and wants to have time with people."

Archbishop Jean Jadot, whose role is somewhat like that of an advance man for a political campaigner, was talking about the difficulties in keeping to schedule for Pope John Paul II's visit to Washington in 10 days.

The archbishop, who is the Vatican's representative to this country, arrived in good time last night for a reception in the patio garden at the Organization of American States.

The reception, first of its kind, was given by Ambassador Gale McGee, the OAS representative from the United States, who wanted to bring together OAS officials and key congressmen in the area of Latin-American affairs.

"I wanted to do this because there's been a gap in exchanges between my colleagues at OAS and the senators and congressmen who deal with Latin-American matters," McGee explained.

Among the guests were the two senators from South Dakota, George McGovern, the Democratic candidate for president in 1972, and Larry Pressler, who has announced as a Republican candidate for 1980.

Jadot, a tall, slightly built Belgian, is the apostolic delegate to the United States and also the Holy See's permanent observer at OAS. The pope is scheduled to make a brief stop at the OAS headquarters building on Oct. 6, his first day in Washington.

"When I saw the pope a few weeks ago," the archbishop said, "he told me he wanted this to be a pastoral, not a political trip."