US troops would probably stay in Iraq for a "protracted period" despite gradual withdrawal, US Defense Secretary Robert Gates said on Sunday.

"Assuming the conditions prevail in Iraq that allow us to continue the draw down that the president has talked about, the idea is that we would have a much more limited role in Iraq for some protracted period of time, a stabilizing force," he told ABC News, "a force that would be a fraction of the size of what we have there now."

However, he did not elaborate on the number of the "fraction," only saying it has to be decided on after consultation with Iraqis to "see what they're prepared to accept."

Gates said, as recommended by Gen. David Petraeus, US troops in Iraq would take a transition in their role from combating to enhancing border security, fighting terrorists and training Iraqi forces.

When asked by the TV host if US presence in Iraq will last 50 years like in South Korea, Gates said "history remains to be written."

"If we leave Iraq in a situation where it's stable and where they are making good progress, then probably not," he said, "But if we leave an Iraq where there is chaos or instability, where al-Qaida has the chance to come back, then you could have substantial forces for some protracted period of time."

After Bush announced a gradual reduction of about 30,000 troops from Iraq by next July, Gates said on a Friday's news conference that it would possible to further cut troop levels from about 130,000 to 100,000 by the end of next year if Iraq situation continues to improve.

However, the Bush administration's withdrawal plan is still short of satisfying Democrats and most public. Demanding much larger size of reduction, Democratic lawmakers are preparing to submit another defense bill next week to push in Congress for a more significant withdrawal of troops from Iraq.

Thousands of people rallied near the White House on Saturday and lashed out Bush's latest speech and the government assessment report on Iraqi situation that both praised "progress" in Iraq brought by US troop surge and defended the current Iraq policy. They marched to the Capitol Hill later in the day as a move to call for more lawmakers to support the bill on withdrawal.

(Xinhua News Agency September 17, 2007)