Acknowledging mistakes in Iraq by the Bush administration, leading Republicans expressed reluctance Sunday that the White House replace Defense Secretary Donald H. Rumsfeld (search), who has lost the confidence of some GOP lawmakers over the conduct of the war.

The chairman of the Senate Armed Services Committee said a change at the top of the Pentagon would be too disruptive, given the elections scheduled in Iraq for Jan. 30. Sen. John Warner, R-Va., also said the administration was dealing with the missteps that have occurred in the aftermath of the U.S.-led ouster of Iraqi President Saddam Hussein (search).

"We should not at this point in time entertain any idea of changing those responsibilities in the Pentagon," Warner told NBC's "Meet the Press."

Sen. Richard Lugar (search), chairman of the Senate Foreign Relations Committee, added, "We really can't go through that ordeal" now of finding a successor. Rumsfeld "should be held accountable, and he should stay in office," said Lugar, R-Ind.

But Sen. Chuck Hagel, a Vietnam veteran, said he had no confidence in Rumsfeld. Hagel, R-Neb., did not say Rumsfeld should step down.

"I find it astounding. ... Things are worse than they've ever been" in Iraq, Hagel told CBS' "Face the Nation." Hagel said it was up to Bush whether to replace Rumsfeld.

More than 1,300 American troops have died since the war began in March 2003. On Sunday, car bombs rocked Iraq's two holiest Shiite cities, killing 62 people and wounding more than 120. In Baghdad, the capital, dozens of gunmen killed three Iraqi election officials during an ambush on a car in the middle of morning traffic.

U.S. troops in Kuwait have complained to Rumsfeld about long deployments and a lack of armored vehicles and other equipment.

Rumsfeld, who agreed to Bush's request this month to stay in the Cabinet during the president's second term, won a vote of confidence from the White House on Sunday.

"Secretary Rumsfeld is doing a spectacular job," the president's chief of staff, Andrew Card, told ABC's "This Week."

"The president has provided good direction for our military, and Secretary Rumsfeld is transforming our military to meet the threats of the 21st century," Card said.

While security remains a problem in Iraq, Card said the growing economy and the establishment of the educational and electrical systems in the country were positive developments, Card said.

"There are no guarantees, but we'll work hard to provide security," for the elections, Card said. "It'll be a wonderful success story."

Critics have raised questions again about whether enough U.S. troops are in Iraq to bring security. Iraq's interim president, Ghazi al-Yawar, said last week the U.S.-led coalition made a mistake by dismantling Iraqi security forces after last year's invasion.

Iraqi leaders have also said that former army officers and police officers with clean records should be reinstated to help organize the Iraqi military. On Sunday, Sen. Carl Levin, D-Mich., said he supported that idea, and the United States also must reach out to Arab countries to help convince Iraq's Muslims of the Sunni sect to participate in the election despite the increased violence.

The Bush administration's biggest mistake in Iraq was the rapid disbanding of military forces "and not trying to maintain some of it in place to have continuity and to rapidly put together a security force," Warner said.

Rumsfeld's performance has also come under criticism even from congressional Republicans, including GOP Sens. Trent Lott of Mississippi and John McCain of Arizona.

Lott said last week that Rumsfeld did not listen to uniformed officers and that Bush should make a change at the Pentagon in the next year or so.

Warner said Sunday that Bush should stay the course, especially with the Iraqi vote next month.

"We are going to have a tough period after that election, and we should press our confidence in the commander in chief and his principal subordinates," Warner said.

Card said Rumsfeld has a good relationship with Congress and "knows the budgets that are needed to fight the war."

At the same time, Rumsfeld also must oversee the transformation of the military "to meet the threats of the 21st century, and that transformation is controversial," Card said.

"I'm sure that some of the people that are stuck in the past don't want to see the military transformed."