A midlevel State Department official is heading an 11th-hour U.S. lobbying effort to soften language hostile to Israel in draft documents prepared for the U.N. conference on racism.

Michael Southwick, a deputy assistant secretary of state, was due to join conference delegates Thursday in Durban, South Africa, where the eight-day conclave opens on Friday.

State Department spokesman Richard Boucher said Southwick and a small number of other officials will be "working the hallways" in search of compromise language acceptable to the United States.

"How that process goes will determine the extent and nature of our participation in the conference," he said.

Regardless of how successful the lobbying effort is, Secretary of State Colin Powell will not attend. He decided earlier this week to stay away because of Arab-backed language in the draft documents accusing Israel of discriminatory treatment of Palestinians.

A senior U.S. official, who asked not to be identified, said that if the lobbying effort bears fruit, Southwick will occupy the U.S. chair at the conference. Otherwise, it will remain empty.

President Bush said last Friday no U.S. delegation will participate at the conference "so long as they pick on Israel."

On Wednesday, the American Civil Liberties Union joined a diverse array of civil and human rights groups in urging full U.S. participation at the conference.

"America must establish its world leadership in combating racism and racial discrimination by sending a full and high-level delegation to the conference," said Laura W. Murphy, director of the ACLU's Washington national office.

William Shulz, executive director of Amnesty International, said in a statement, "We believe the best way to resolve conflict is to get into the game and not sit in the stands."

The absence of a high-level representative in Durban suggests "stark disinterest" in the United States having a leadership role, Shulz said.