Washington ? Kansas Sen. Sam Brownback and another Republican member of Congress urged U.N. Secretary-General Kofi Annan to resign in protest if the United Nations fails to take aggressive steps to stop the violence in the Darfur region of Sudan.

“We cannot wait any longer for credible action in Darfur,” Brownback said Tuesday. “The time is now for the secretary-general, Kofi Annan, to lead or leave.”

Rep. Frank Wolf, R-Va., said he does not blame Annan for the violence in Darfur, but said his resignation could jolt the Security Council into imposing sanctions and taking other steps to pressure the Sudanese government.

“Resigning out of protest is an act of great moral leadership,” Wolf said.

At the United Nations, spokesman Fred Eckhard stressed that Annan’s authority is largely limited, with member states having the real power.

“The most the secretary-general can do under the charter is bring to the attention of the Security Council any threat to international peace and security,” Eckhard said.

Annan on Tuesday said the Security Council should take urgent action to stop the violence. He said council members should consider imposing sanctions and pressed for the prosecution of those accused of abuses.

Brownback and Wolf spoke at a news conference at the Capitol one day after a U.N. panel reported that the violence in Darfur were crimes against humanity. The panel did not describe it as “genocide,” the term used by the Bush administration.

Wolf played down the distinction as “a semantical issue,” noting the report highlights the killings, rapes and forced displacement of Darfur residents by the government of Sudan and allied Arab militias.

Other lawmakers criticized the panel’s refusal to call it genocide. “The killing is undoubtedly racially and religiously motivated,” Rep. Ed Royce, R-Calif., chairman of the International Relations Africa subcommittee, said in a statement.

The conflict in Darfur, a large region in western Sudan, began two years ago when rebels took up arms against what they saw as the Arab-dominated government’s discrimination against Sudanese of African origin. The government and an allied Arab militia, the Janjaweed, have been accused of a brutal counterinsurgency campaign.

The United Nations says the conflict has killed 70,000 people since March, mostly from disease and hunger. Others say the figure is much higher. About 2 million people are believed to have been displaced, many living in refugee camps.

Wolf and Brownback praised the Bush administration’s efforts to pursue international sanctions and provide relief to refugees.

“The problem to date has not been the United States, the United States leadership. The problem to date has been inaction by the United Nations,” Brownback said.

The two lawmakers said their calls for Annan to consider resigning were unrelated to similar demands made by other U.S. lawmakers as a result of the U.N. oil-for-food scandal.