New York Sen. Hillary Rodham Clinton was headed for a public showdown Thursday with Secretary of Defense Donald Rumsfeld after he reversed course at the last minute and said he would testify before a Senate committee.

Clinton, D-N.Y., had criticized Rumsfeld in a letter and at a hearing Wednesday for choosing not to appear at a public hearing before the Armed Services Committee on Thursday. Clinton is a member of the committee.

The senator, who has not called for Rumsfeld's resignation, as have other Democrats, was strikingly critical of his track record Wednesday.

Before he reversed course, she wrote to him that "a public appearance before the committee is long overdue," noting it has been nearly six months since his last such testimony.

The Pentagon announced Wednesday night that Rumsfeld had changed his mind and would testify in the hearing.

After the announcement, Clinton said Rumsfeld's "11th-hour decision to reverse course and appear at tomorrow's open Armed Services Committee hearing is the right one, as the committee and the American people should hear directly from the top civilian leader at the Pentagon, the person most responsible for implementing the president's military policy in Iraq and Afghanistan."

The Pentagon announcement came as Clinton and other Senate Democrats led a new round of attacks on Rumsfeld's record in running the Iraq and Afghanistan wars.

"I for one am deeply disturbed at the failures, the constant, consistent failures of strategy with respect to Iraq, Afghanistan and elsewhere," Clinton said Wednesday at an ASC hearing featuring a deputy defense secretary. "And I don't think that those failures can be appropriately attributed to our military leadership."

She argued that if Rumsfeld can meet senators privately, as he did Tuesday and planned to do Thursday, he should do so publicly.

"The American people deserve to see the principal decision maker when it comes to these matters that are putting our young men and women at risk," she said. "More than 2,500 of them have lost their lives. And this secretary of defense, I think, owes the American people more than he is providing."

The top Republican and Democrat on the committee, Sens. John WarnerR-Va., and Carl Levin, D-Mich., had asked Rumsfeld in a July 26 letter to appear before the committee, saying they had questions about Iraq, Afghanistan and the recent violence in Lebanon between Israeli forces and Hezbollah.

The panel is also scheduled to hear testimony from Gen. Peter Pace, chairman of the Joint Chiefs of Staff, and Gen. John Abizaid, who leads Central Command.

Clinton's own position on Iraq has drawn fire from members of the anti-war wing of the Democratic Party, some of whom argue that her 2002 vote authorizing the war and continued support for the overall mission hurt her chances as a presidential candidate in the Democratic primary in 2008.

At a press briefing earlier Wednesday, Rumsfeld suggested that complaints about his decision could be politically motivated.

"Let's be honest: Politics enters into these things, and maybe the person raising the question is interested in that," said Rumsfeld, without identifying anyone.

The defense secretary said he had testified in the past and was not reluctant to face off against some of the committee's more vocal war critics, including Sen. Edward M. Kennedy, D-Mass.

Rumsfeld last appeared before the committee on Feb. 7, when he and Pace were questioned about the war's strain on the military.

In the six months since, the number of U.S. troops in Iraq has dipped but now is back up to about 133,000, as part of an effort to quell the violence in Baghdad. The total could exceed 135,000 in the weeks and months ahead.