The New York Times: James Billington, the librarian of Congress, is in Iran this week on the first visit by a notable U.S. government official to that country in 18 years, administration officials said. The unannounced visit was confirmed by the Library of Congress on Wednesday after it was disclosed by the Federation of American Scientists, an independent policy group in Washington. The New York Times

By Douglas Jehl

WASHINGTON - James Billington, the librarian of Congress, is in Iran this week on the first visit by a notable U.S. government official to that country in 18 years, administration officials said.

The unannounced visit was confirmed by the Library of Congress on Wednesday after it was disclosed by the Federation of American Scientists, an independent policy group in Washington. The library said that the purpose of Billington's trip was "purely cultural" and that he was traveling at the invitation of Muhammad Kazem Mousavi Bojnourdi, the director of the National Library of Iran.

While cultural visits have occurred before, administration officials said they believed Billington to be the highest-ranking American official to travel to Iran since 1986, when Robert McFarlane, then the national security adviser, led a delegation that made a secret visit in an attempt to cultivate a relationship with moderates in the Iranian government.

The State Department spokesman, Richard Boucher, said he would not "attach any special importance" to Billington's visit.

Relations are tense between Washington and Iran over Tehran's nuclear program. This week also is the 25th anniversary of the takeover of the U.S. Embassy in Tehran and the seizing of hostages during Iran's Islamic revolution in 1979, which prompted Washington to sever diplomatic relations.

An administration official said Billington's travel had been approved by the State Department and the National Security Council as a "people-to-people outreach that falls short of supporting the government of Iran." A congressional official said Senator Ted Stevens, Republican of Alaska, who is chairman of the Joint Committee on the Library, also approved.

In the past, the United States has used scientific and cultural exchanges with the Soviet Union, China and other countries to smooth the way for improvements in diplomatic and political relations. Iran's openness to the visit is also telling because it has resisted some past efforts by the United States to establish closer cultural ties.

Administration officials said they regarded the trip as a step toward promoting a Middle East partnership authorized by Congress in 2002 to encourage democracy and human rights in the region. They said there was no particular significance in the timing of the trip, and said the decision not to publicize it reflected concerns about security and Iranian sensitivities.

The Federation of American Scientists said the trip had been arranged by a private group, Catalytic Diplomacy, at the request of the Library of Congress.