US officials say that November's figures are low due to constraints on the ground and the lack of co-operation from foreign governments, particularly Syria, where most Iraqis fled to after the 2003 invasion.


Syria had not allowed US interviewers to vet refugees between May and mid-November.


Legislators and refugee rights groups are blaming Washington for being too slow and for not doing enough to overcome bureaucratic delays and internal disagreements between the agencies in charge.


The United Nations high commissioner for refugees estimates that more than two million Iraqis have fled their country, with most of them in camps in neighbouring Syria.