Iraqi Prime Minister Haider al-Abadi's office condemned Thursday outgoing US army chief General Raymond Odierno's "irresponsible" statement on the possibility that Iraq might be partitioned.

It was "an irresponsible statement and reflects an ignorance of the Iraqi reality," Abadi's media office said.

Odierno, who served as the top US commander in Iraq from 2008 to 2010, said Wednesday that partitioning the country "is something that could happen" and "might be the only solution, but I'm not ready to say that yet."

The United States is a key partner in Iraq's battle against the Islamic State group, leading a coalition that is carrying out air strikes against the militants and is training Baghdad's forces.

The issue of partition, which would presumably take place along ethnic and sectarian lines, is an extremely sensitive one for Baghdad, which is fighting to regain territory lost to and keep the country united

But there are deep divides among Iraq's three main communities: Shiite and Sunni Arabs, and Kurds.

Kurds dominate the country's north and Shiites the south, while the Sunni Arab population is distributed across western, northern and central Iraq.