Nov. 14 (Bloomberg) -- The U.S. Senate opened debate today on measures that would put the chamber on record for the first time asking President George W. Bush to set limits for keeping American troops in Iraq.

The Bush administration ``needs to explain to Congress and the American people its strategy for the successful completion of the mission,'' say resolutions introduced separately by both Republicans and Democrats.

Both parties also would require that Iraq's rival political factions be told they must make the compromises necessary to achieve a stable government, united against the insurgency, which will allow U.S. troops to leave.

While the measures express a non-binding ``sense of the Senate,'' together they're ``early pressure on a major U.S. military operation, in contrast to the Vietnam War'' where congressional resistance didn't occur until the early 1970s or about eight years after the start of the major military build- up, said Louis Fisher, a senior specialist on congressional war powers for the nonpartisan Congressional Research Service.

The measures will prove attractive to Republicans up for re-election next year who want ``to distance themselves from the White House,'' Fisher said.

Bush's approval rating is at a record low in recent polls. A survey released today by CNN, USA Today and the Gallup Organization showed 37 percent approve of the job he's doing and 60 percent disapprove. A Newsweek magazine poll released yesterday found an approval rating of 36 percent and a disapproval rate of 58 percent.

Setting Policy

The Republican resolution is sponsored by Majority Leader Bill Frist of Tennessee and the chairman of the Armed Services Committee, John Warner of Virginia. The Democratic version is pushed by their counterparts, Minority Leader Harry Reid of Nevada and Carl Levin of Michigan, ranking Democrat on the armed services panel. Votes on the amendments are likely tomorrow.

Democrats including Levin, Russ Feingold of Wisconsin, Chris Dodd of Connecticut and John Kerry of Massachusetts took turns on the Senate floor today lambasting Bush's handling of the conflict in Iraq.

``We need to move forward with fixing the mess the administration has created in Iraq,'' said Kerry, his party's 2004 presidential nominee and a persistent critic. ``Fighting for the right policy for our troops sends them exactly the right message to the troops: that we take the decision to put them in harm's way seriously and that our democracy is alive and well.''

Setting Policy

The Iraq resolutions would be attached to the Senate's fiscal 2006 defense authorization bill, which sets military policy and has become a vehicle for lawmakers' efforts to weigh in on the administration's handling of the conflict.

The bill already includes amendments governing the treatment of enemy combatants, the rights of detainees at Guantanamo Bay, Cuba, and the nature of any secret U.S. detention facilities.

The amendments under discussion today both say the administration should make 2006 ``a period of significant transition to full Iraqi sovereignty, with Iraqi forces taking the lead for the security thereby creating the conditions for the phased redeployment of U.S. forces from Iraq.''

Progress Reports

The Republican amendment requires an unclassified White House report within three months of the authorization bill's passage and every three months thereafter outlining the current military situation, the status of Iraqi forces troop training and status of efforts ``to convince Iraq's main communities to make the compromises necessary to forge a broad-based and sustainable political settlement.'' The Democrats' version requires the first report within 30 days.

In one of the biggest differences, the Warner-Frist version says ``the people of Iraq should be advised'' that ``U.S. military forces should not stay in Iraq any longer than required.'' The Reid-Levin version is more pointed, saying Iraqis should be told ``United States' military forces should not stay in Iraq indefinitely.''

The U.S. will keep about 159,000 troops in Iraq through the Mideast nation's Dec. 15 national election. This was the troop level for the elections in January and is higher than at any time since the March 2003 invasion, according to U.S. Central Command figures.

This force could be reduced in a ``fairly rapid'' way to about 138,000 if insurgent attacks are reduced and the election is a success, Lieutenant General James Conway of the Joint Chiefs of Staff told a Pentagon press conference Nov. 3.