Declining to give any time frame for the withdrawal of US troops from the country, Iraqi Prime Minister Nouri al Maliki has said he won't rule out the possibility of American forces remaining there for another five years.

"Anything specific I can not give, neither us nor the US government can set up a timetable," Maliki said.

Just eight months ago, Maliki had told a news channel that he wanted Iraqi security forces to take over from US troops by June.

"It all depends on the success and the agreements between us. Neither we nor the US government want to lose all the progress we have made," Maliki said on Friday during an interview to the ABC television network.

Maliki has, in the past, seemed impatient for the Iraqi army and police to take over from the United States, perhaps to emphasise his nationalism in the face of an occupying army.

But with the US now making some progress on the ground against al Qaeda, Maliki may have changed his views, the channel said.

In fact, he said if the United States were to withdraw too soon, Iraq could be plunged into civil war.

"When we can establish security, then our security forces will be ready through training to take over," he said.

Asked when he thought the last US soldier would leave Iraq, Maliki said, "this depends on the success we can achieve".

Maliki admitted that the Iraqi parliament was not moving ahead to pass laws as quickly as he would like, but said this was due to political infighting among different groups in the Parliament.

He seemed strangely unconcerned about the mounting pressure in the US Congress for a troop withdrawal based on the apparent lack of political progress in Baghdad, ABC said.

"I don't think there is a correlation between the presence of US forces and the Iraqi parliament," he said.

Reacting on the US Defense Secretary Robert Gates' recent comments regarding his frustration at the lack of political progress in Iraq, even as more than 3,000 US soldiers have died in the country, Maliki said, "Iraq has just emerged from dictatorship into a national unity government, it is progressing, but very slowly".