US President George W Bush has no plans to withdraw troops from Iraq now, the White House said, despite increasing pressure from members of his own Republican party for a change in war strategy.

But Senate Democrats planned to hold votes on troop pullouts, hoping to capitalize on Republican defections to build a congressional majority around an exit strategy.

 'A growing number of Republicans are now speaking against the failed strategy in Iraq, and that's good,' said Senate Majority Leader Harry Reid.

'I think we will find the next couple of weeks whether the Republicans who have said publicly they think the present course should change are willing to vote with us,' the Nevada Democrat said.

At least one such Republican said she was willing to do so. Maine Sen Olympia Snowe, an early critic of Bush's policy of sending more troops to Iraq this year, said she was ready to vote for binding legislation requiring a troop withdrawal.

The White House denied a New York Times report that debate was intensifying over whether Bush should try to prevent more Republican defections by announcing intentions for a gradual withdrawal of troops from high-casualty Iraqi areas.

'There is no debate right now on withdrawing forces right now from Iraq,' White House spokesman Tony Snow said.

Following recent calls for a change in strategy by lawmakers such as Sen Richard Lugar, the ranking Republican on the Senate Foreign Relations Committee, the Times said officials fear the last pillars of political support among US Senate Republicans for Bush's Iraq policy were collapsing.

An upcoming administration report to Congress assessing progress in Iraq is expected to further fuel the debate. Administration officials say the report, due by July 15, will show a mixed review on progress being made.

The report, expected to be delivered to Congress by the end of the week, 'will present a picture of satisfactory progress on some benchmarks and not on others. This is to be expected given the report is a preliminary snapshot of what are the early stages of the full surge,' a senior administration official said.

Bush has been steadfast against setting deadlines for withdrawing troops and has warned that prematurely pulling forces out of Iraq would hand US enemies a victory and risk America's security.

He has repeatedly made the point that when conditions warrant, US troops will be brought home, Snow said.

'But the idea of trying to make a political judgment rather than a military judgment about how to have forces in the field is simply not true,' Snow said.

Senate debate on Iraq would be part of work on a defense policy bill, beginning with a vote, possibly on Tuesday, on a plan by Virginia Democratic Sen Jim Webb to establish minimum rest times between deployments for troops in Iraq, some of whom have done several tours of duty.

A vote would follow on a withdrawal plan by Michigan Democratic Sen Carl Levin, the Armed Services Committee chairman. It is expected to require a reduction of US troops to start soon with a goal of finishing the drawdown next spring.

Reid acknowledged he did not know whether he had the votes to overcome Senate procedural hurdles.Reuters