WASHINGTON -- Addressing rising concerns over the war in Iraq, an overwhelming majority of the U.S. Senate yesterday voted to require the Bush administration to lay out a plan for accomplishing the U.S. mission there and to report on it quarterly to Congress.

Seventy-nine senators voted for an amendment to a spending bill stating that 2006 should be "a period of significant transition" in which Iraqi security forces take the lead in protecting their citizens, creating conditions for a "phased" withdrawal of U.S. forces.

The Senate earlier rejected a stronger Democratic proposal, 58-40, that called for "a campaign plan with estimated dates for the phased [withdrawal] of U.S. Armed Forces from Iraq," and most Republicans insisted the final vote was not a repudiation of the Bush administration or even a change in policy.

Pennsylvania Sen. Rick Santorum said he considered voting against the measure because he saw it "as sort of a nothing vote" that amounted to "Congress just sort of puffing its chest a little bit."

But Senate Minority Leader Harry Reid called the vote a bi-partisan signal to the administration that Republicans and Democrats were not content to "stay the course."

"This is clearly a vote of no confidence in what President Bush is doing in Iraq," Mr. Reid said.

Along with Mr. Santorum among senators in this area, Sens. Arlen Specter, R-Pa., Jay Rockefeller, D-W.Va., Mike DeWine, R-Ohio, and George V. Voinovich, R-Ohio, voted for the amendment. Sen. Robert Byrd, D-W.Va., voted against it.

White House spokesman Allen Abney said the White House was "happy to report on the progress."

Democrats pointed out that the amendment says the administration's quarterly reports must include an explanation of the conditions under which Iraq would be considered stable, to clear the way for a withdrawal.

That includes updates on the status of training of the Iraqi Armed Forces, special forces units, and regular police, as well as on the ability of all branches of the Iraqi government to take over Iraq's security forces.

The measure, sponsored by Senate Majority Leader Bill Frist, R-Tenn., and Armed Services Committee Chairman John Warner, R-Va., was essentially a revision of a Democratic proposal. But Republicans took over the measure -- in what Mr. Warner said was an effort to make it bipartisan -- and stripped out what they viewed as the Democrats' most dangerous demand: setting a date for withdrawal.

Mr. Frist compared that provision to a "cut and run" strategy and said publishing a timeline for retreat would encourage the terrorists and confuse the Iraqi people.

Thirteen Republicans voted against the Frist-Warner amendment. Sen. John McCain, R-Ariz., said he objected to any language referring to a withdrawal and said the focus should be on completing the mission successfully, even if it requires more troops.

Other Republicans said their leaders were responding to growing discomfort among Americans about the war.

In a separate action yesterday, 84 senators also approved new rules governing the legal rights of prisoners at Guantanamo Bay, Cuba, to fill what the measure's sponsors described as their void in leadership on the issue.

Sen. Lindsey O. Graham, R-S.C., Sen. Jon Kyl, R-Ariz., and Sen. Carl Levin, D-Mich., won bipartisan support for a streamlined set of legal procedures.

Under current Bush administration procedure, a panel or tribunal of three military officers determines whether a prisoner should be defined as an "enemy combatant." The classification is reviewed annually.

Mr. Graham's new rules would give detainees a one-time chance to challenge that classification before the U.S. Court of Appeals for the D.C. Circuit. If the challenge fails, the detainees would be bound by the decision of the annual review board.

The new rules also require the U.S. Court of Appeals for the D.C. Circuit to review all decisions by U.S. military commissions that sentence Guantanamo prisoners to death or to 10 or more years in prison. Detainees who are convicted of a crime and receive a penalty of less than 10 years imprisonment would also have the option to ask the court to review their case.

Mr. Graham acknowledged that if a joint House-Senate committee gives final approval to his legislation, Guantanamo Bay prisoners who are not U.S. citizens would not have access to writs of habeas corpus, which gives prisoners the right to challenge their confinement.

The Supreme Court has said federal courts may hear habeas petitions from Guantanamo Bay detainees, but Mr. Graham argued that the previous understanding of U.S. law was that aliens outside the U.S. should not have access to federal courts -- and his legislation clarifies that intent.

That was one of many concerns that Senate Judiciary Chairman Arlen Specter raised about the proposal.

Mr. Specter was the only Republican senator to vote against Mr. Graham's proposal, which passed 84 to 14.

The Pennsylvania Republican described Mr. Graham's language directing the U.S. Court of Appeals for the D.C. Circuit to review the detainee cases as "blatant court-stripping in the most confusing way possible," because he said the language of the legislation gives exclusive jurisdiction over the detainee cases to the Circuit Court -- taking away jurisdiction from the Supreme Court.