UNITED NATIONS — As if the pressures to balance international interests inside Turtle Bay are not enough, a Washington trip Secretary-General Ban plans today may also involve tiptoeing over the nuances of American politics.

On the surface, the two-day trip to the capital is mostly a courtesy call. It will include an afternoon White House meeting with President Bush, followed by a short press conference, several meetings with key members of Congress, and an evening reception co-hosted by the new chairman of the House International Relations Committee, Rep. Tom Lantos, a Democrat of California, and by the top Republican on the Committee, Rep. Ileana Ros-Lehtinen, a Republican of Florida.

U.N. chiefs, while headquartered in New York, rarely escape Washington politics, and Mr. Ban will have to orient himself to new realities in Washington, where Democrats control Congress and Mr. Bush enters the last two years of his administration.

Mr. Ban, who refers to himself as a “bridge builder,” has reached out for advice from Americans of both parties and, in a rare move for a secretary-general, is considering recruiting at least one adviser identified as a Republican. That attempt was met with a lot of Turtle Bay “resistance” by insiders, said a Washington source who asked for anonymity.

Both Democrats and Republicans will attend tonight’s reception in the Washington residence of a former member of the American mission to the United Nations, Esther Coopersmith.

A close personal friend of Mr. Ban’s predecessor, Kofi Annan, Mr. Lantos, will cohost, greeting Cabinet members, legislators, and the president of the International Monetary Fund. After meeting Mr. Ban twice before, Mr. Lantos discovered the two “share many interests, like U.N. reform,” Mr. Lantos’s spokeswoman, Lynne Weil, said.

The lone American joining Mr. Ban’s entourage today was a close adviser to Mr. Annan, Robert Orr. Hand-picked by the former U.N. administration to handle the transition period, Mr. Orr joined Turtle Bay after serving in Washington under the high-ranking Democratic foreign-affairs official, Richard Holbrooke.

It is not clear yet what role Mr. Orr will play in Mr. Ban’s administration, although he is said by insiders to be close to the new secretary-general.

Unlike Mr. Annan, who owed his tenure to the Clinton administration and who was heavily influenced by Mr. Holbrooke and the billionaire philanthropist and political funder George Soros, one of Mr. Ban’s crucial stops on his last year’s campaign for the U.N. post was Mr. Bush’s White House.

In September, after a first, inconclusive straw poll among the 15 members of the Security Council, Mr. Ban, who was then South Korea’s foreign minister, joined President Roh on a Washington trip. It was then that Mr. Roh convinced his American counterpart to back the Korean candidate. Mr. Bush even “dropped in” on one of Mr. Ban’s Washington meetings, and the two spoke for half an hour, according to a former Korean adviser. After that, the fate of the U.N. leadership was all but sealed.

Since then, Mr. Ban had often consulted the American ambassador to the United Nations, John Bolton, who was seen by Turtle Bay insiders as an enemy. Mr. Bolton left Turtle Bay in December after U.N. insiders campaigned against his Senate confirmation.

Mr. Annan’s former deputy, Mark Malloch Brown, said last week in an interview with British Channel 4 television that he did not think Mr. Bolton was “a very good ambassador,” and he added, “I was very pleased, in terms of sequence, that I could at least hold the door for him to go out first.”

Asked for response, Mr. Bolton told The New York Sun, “Who cares what he thinks?”

Many at the United Nations now believe that the Bush administration is wounded and can all but be ignored.

But while Mr. Ban told the Sun in an interview that he will seek “close dialogue with the Democratic leadership,” he also added that Republican “participation and understanding and support” are very important to him.