BAGHDAD: Iraqi Prime Nuri al-Maliki rejected any foreign interference in his country and called on Iraqis to unite, days after US criticism of the slow pace of national reconciliation.

"We will not allow Iraq to become an arena for conflicts or a space for any foreign project," said Maliki during a visit to the western Anbar province, once a hotbed of a fierce anti-US insurgency.

"We will not allow anyone to interfere in our affairs or supervise our political process and our national reconciliation," Maliki said in a statement released by his office.

"I call on you (to unite)... and reject sectarian strife. We want a strong and united coalition of all Iraqis because the biggest challenge is to confront interferences that come from everywhere," Maliki said.

US Vice President Joe Biden, who has been appointed by President Barack Obama as his pointman in Iraq, has repeatedly voiced concern about lingering feuds between Iraq's Shiite, Sunni and Kurdish communities.

On a trip to Baghdad last week Biden urged Iraqi leaders to speed up the process of national reconciliation, warning of a "hard road ahead if Iraq is going to find lasting peace and stability."

A senior US official told reporters during the trip that Biden had also warned that Washington would disengage politically if violence in Iraq spiked.

"If it actually reverts to violence, then that would change the nature of our engagement. He was quite direct about that," the official said.

Maliki, who is due to visit Washington later this month, stressed that Iraqis of all ethnic and religious backgrounds must rally around "the national project" of reconciliation.