WASHINGTON, Aug 8: A growing number of US lawmakers, even in the ruling Republican Party, believe that the US plan to begin withdrawing troops from Iraq by next spring cannot be implemented particularly because Iraqi forces are not yet ready to conduct combat operation without US support.

Gen. George W. Casey Jr., commander of the multi-national forces in Iraq, suggested last week that US troops in that country could be greatly reduced next spring if internal forces are strengthened.

Gen. John Abizaid, who heads the US Central Command, also said recently that he also has a plan to reduce troops by 20,000 to 30,000 next year. But other Pentagon officials have acknowledged US troops cannot withdraw until Iraqis can assume responsibility for the country’s safety.

The debate over the possible withdrawal of US troops from Iraq follows the death of 21 US Marines last week.