Backed into a corner and influence waning, the United States has in recent weeks been promoting a plan to create an autonomous Sunni region in western Iraq, officials from both countries told Middle East Eye.

The US efforts, the officials say, come in response to Shia Iraqi parties' attempts to expel American troops from their country.

Iraq represents a strategic land bridge between Iran and its allies in Syria, Lebanon and Palestine.

Establishing a US-controlled Sunni buffer zone in western Iraq would deprive Iran of using land routes into Syria and prevent it from reaching the eastern shores of the Mediterranean.

For Washington, the idea of carving out a Sunni region dates back to a 2007 proposition by Joe Biden, who is now vying to be the Democratic Party's presidential candidate.