WASHINGTON — Iraq's leaders should ask "sooner rather than later" for a sizeable US troop presence there into 2012, a key US lawmaker said Wednesday, warning that too small a number would imperil fragile gains.

"We've won there, we should not give up that victory," House Armed Services Committee Chairman Buck McKeon told reporters in a roundtable interview with a year-end deadline for a US withdrawal fast approaching.

The Republican representative said he had met months ago with a top Iraqi lawmaker to discuss prospects that the strife-torn country's government would ask Washington to keep a residual force deployed there.

McKeon said he told the Iraqi official "we're not going to suggest leaving troops there if you don't ask for them," but heard back "well, we don't want to ask for them if we think you're going to say no."

"I encourage them to ask us sooner rather than later," said McKeon, adding that the figure discussed in Baghdad was "considerably higher" than the 3,000 to 4,000 troops described in recent US news reports.

The US lawmaker said was was "not overjoyed" when he saw those reports, saying commanders in the field had told him "we shouldn't go below ten (thousand), either that or get everybody out."

US President Barack Obama's administration has since denied that any final decision has been made.

"Maybe they'll pull back and give it a little more thought. I think that would be a good thing," said McKeon, adding that US troops were needed to provide security, train Iraqi forces, and in case of "contingency flare-up, so we wouldn't have to go back in and start all over again."

And he said that Washington's Status of Forces Agreement with Baghdad called for withdrawing all US troops no later than December 2011, leaving just 165 or so to protect the US diplomats and civilian workers who will carry on.