|Less than 50,000 US troops remain in Iraq and are scheduled to leave the country at the end of 2011 [AFP]
The chairman of the US military's joint chiefs of staff has said that Iraq must decide "very soon" if it needs American forces to stay beyond a planned departure at the end of this year.
Admiral Michael Mullen is the latest US official to visit Baghdad in the run-up to the upcoming pullout, with the same message that Iraq must make an urgent decision on troops.
"Should the Iraqi government desire to discuss the potential for some US troops to stay, I am certain my government will welcome that dialogue," he said on Friday.
"But it needs to start soon, very soon, should there be any chance of avoiding irrevocable logistics and operational decisions we must make in the coming weeks.
"Time is running short for negotiations to occur."
Al Jazeera's Jane Arraf, reporting from Baghdad, said that Mullen identified areas in which the Iraqis might require help.
"He identified air defences, intelligence and sustainment [meaning] the ability to provide food, water and equipment," she said.
"Those are things the US would like to continue to help with."
She said it was clear that the US "would like the Iraqis to ask, but they need them to ask pretty much now".
Mullen's public comments came a day after Nouri al-Maliki, the Iraqi prime minister, said the Iraqi army was up to the task of maintaining security.
"Prime Minister Maliki said the armed forces and the Iraqi security forces were able to take responsibility, and that they worked with professionalism," a statement from al-Maliki's office said on Thursday.
His remarks to Mullen reiterated those he made to John Boehner, the speaker of the US House of Representatives, who visited Iraq last weekend.
Sandwiched between Boehner's and Mullen's trips was a visit by General Martin Dempsey, the US army chief of staff.
Fewer than 50,000 US troops are currently stationed in Iraq, down from a peak of nearly 170,000 following the US-led invasion that ousted Saddam Hussein in 2003.
All of those troops must withdraw from the country by the end of the year, according to the terms of a bilateral security pact.
Robert Gates, US defence secretary, said during an unannounced trip to Iraq on April 8 that American forces were prepared to stay in any role beyond the scheduled pullout, but he too said time was running out for Iraq to ask.
"My basic message to them is [for us to] just be present in some areas where they still need help. We are open to that possibility," he said. "But they have to ask, and time is running out in Washington."
A senior US military official said last week that Iraqi leaders should not expect US forces to return to help in a crisis after they have pulled out.