The US Senate on Wednesday downed a Democratic effort that would have set an April 2008 deadline for the removal of all American combat troops from Iraq after a rare all-night debate.

The bill fell just eight votes shy of the 60 needed to move past the debate towards a final vote. 

"Regrettably, Republicans chose to block this amendment," said Senate Majority Leader Harry Reid (D-Nevada). "They chose to continue protecting our president instead of our troops."

The withdrawal plan, tacked as an amendment to the annual defense authorization bill, was co-sponsored by Democratic Senators Carl Levin of Michigan and Jack Reed of Rhode Island.

However, despite anti-war tendencies growing in the senate, differences between Democrats and Republicans maintained the latter's resolve to sink the bill.

Democrats sought to a simple majority vote for the amendments to be adopted, while Republicans insisted on 60 votes, or three-fifths of the Senate. Democrats control the Senate, 51-49.

Four Republicans did switch allegiances and voted with the Democrats, namely Chuck Hagel of Nebraska, Olympia Snowe and Susan Collins of Maine, and Gordon Smith of Oregon.

As senators cast their votes, Secretary of State Condoleezza Rice called upon lawmakers in their offices to try and shore up flagging support for the war.

The Bush administration is under growing pressure to withdraw troops from Iraq, as a recent Iraq situation report pointed out the Iraqi government had missed key political goals set by the US government, causing the four defections above.

Currently around 160,000 US troops are operating in Iraq, with more than 3,600 American soldiers and tens of thousands of Iraqis having been killed since the war started in March 2003.

(Xinhua News Agency July 19, 2007)