A group of US lawmakers allied with the White House called Thursday for an end to the Afghan war, labeling it an unwinnable drain on US "blood and treasure" and comparing it to Vietnam.

"Every dollar spent and every life wasted in Vietnam was just that: A waste," said Democratic Representative Jerrold Nadler. "Afghanistan is the same. Every dollar we spend, every life we waste is a waste."

Some 21 lawmakers have joined the "Out of Afghanistan Caucus" opposing continued combat operations there, according to one of the group's leaders, Democratic Representative John Conyers.

The revolt against President Barack Obama's strategy to turn around the faltering campaign came as the House of Representatives was expected to pass a bill to pump another 37 billion dollars into the wars in Iraq and Afghanistan.

Recent polls have found the US public deeply pessimistic about the Afghan war, with some surveys finding a majority say it was not worth fighting, and growing numbers backing a US pull-out almost nine years after the October 2001 invasion.

The House was also expected to take up an amendment by Democratic Representative Barbara Lee that calls for using the money only "for the safe and orderly withdrawal" of US forces, she told reporters.

"This amendment would require the beginning of the end of this, our longest war," she said, stressing that "the costs of this war in blood and treasure are just too great."

The House was also expected to vote on another Democratic amendment calling on Obama to provide a withdrawal timetable, though enough Republicans and Democrats support Obama's strategy that both measures were expected to be defeated.

"We don't know whether we'll be successful today, but I believe we are standing here to say that we're committed to vote, over and over again, no, no, no," said Democratic Representative Sheila Jackson Lee.

The spending bill under consideration also included nearly three billion in aid for Haiti in the wake of the devastating earthquake there, 701 million dollars of increased US-Mexico border security and 304 million dollars for the response to the catastrophic Gulf of Mexico oil spill.