Maliki's remarks reiterate comments he made last month, when he said he would hold talks with other parties to reach a nationwide consensus on the issue, with US officials pressing Baghdad to decide within weeks whether it wants a longer-term US military presence.
"The decision about the US withdrawal is a huge national task, so I will call all the blocs' leaders to have a dialogue to say whether they want to keep the forces or not," Maliki told a news conference in Baghdad.
"After that, the government will decide on keeping them, or making them leave."
Maliki said on April 26 that he would make such a call after returning from a planned trip to South Korea, which he completed this month.
He has previously alluded to domestic political difficulties he would have in seeking approval in parliament for an extension.