'Nobody knows' when Iraqis will be ready to takeover security

General Richard Myers, the chairman of the Joint Chiefs of Staff, said Iraqi security forces have been given responsibility for security in seven or eight places around the country, including a part of Baghdad.

But at a Pentagon press conference, he acknowledged major uncertainties ahead for the US goal of drawing down its 138,000-strong force next year, and replacing American troops in phases with Iraqi forces.

Asked how soon Iraqi security forces can take the lead in the counter-insurgency, Myers said: "Nobody knows."

"It's event driven. It's going to be ... driven by a lot of events," he said.

"So you can't predict your troop strength based on what you think is going to happen. You have to wait until events on the ground prove it," he said.

Myers said the Iraqi security forces were now 178,000-strong and they were coming on "at a certain rate with certain capabilities. We're not going to bet on that until we have that in hand."

Myers and US Defence Secretary Donald Rumsfeld emphasised that any drawdown of US forces also will depend on progress on the political front toward a constitution and elections, the level of the insurgency, and what they termed the degree of meddling by Iran and Syria.