The White House said the top US and Iraqi national security chiefs discussed the future of their countries' ties on Saturday, two months before all US troops are due to leave Iraq.

During their talks at the White House, US National Security Adviser Tom Donilon and his Iraqi counterpart Falah al-Fayadh "reaffirmed the common vision of a broad, deep strategic partnership between the United States and Iraq as embodied in the Strategic Framework Agreement," spokesman Jay Carney said.

"The two held a far-reaching discussion of the elements of a fully normalized relationship between Iraq and the United States, including education, investment and security."

The meeting came after Iraq's refusal to grant US troops legal immunity prompted President Barack Obama to abandon US plans to keep a residual training force in Iraq after December 31, and to announce all US troops would come home this year.

Carney said Donilon and Fayadh "committed to develop additional mechanisms to establish a continuous strategic dialogue between the United States and Iraq."

Obama announced last week that all US troops will leave Iraq by the end of the year, ending a long war which cleaved deep political divides and estranged the United States from its allies.

After nearly nine years, the deaths of more than 4,400 US troops, tens of thousands of Iraqis and the expenditure of hundreds of billions of dollars, Obama said the last US soldier will leave with his head held high.