The long-awaited announcement of a new Iraqi government, which had been expected on Sunday or Monday, has been delayed.
There have been complex negotiations since an inconclusive general election in March.
The BBC reports that under the constitution, the cabinet must be in place by Saturday. There are 37 posts in all.
Each of the nominations still has to be approved by parliament.
Prime Minister Nouri Maliki had been expected to name his entire cabinet, except for three sensitive posts linked to national security.
But politicians said on Monday that as many as half of the ministerial positions were still undecided.
A spokesman said Mr Maliki would announce "half the new government" at a session of parliament on Monday.
The new cabinet is expected to include all the major factions, including the Kurds, Shia and Sunni Arabs. The BBC says it will be a delicate balancing act for Mr Maliki.