Washington has asked 60 countries to expel alleged Iraqi agents, whom officials claim may be poised to attack US interests overseas.
Two UN-based Iraqi diplomats have already been ordered to leave the US.
Iraq's UN Ambassador Mohammed Al-Douri says the two have been given 72 hours to leave.
The State Department has identified them as Nazih Abdul Latif Rahman and Yehia Naeem Suaoud.
"The two attaches were engaged in activities outside the scope of their official function," the department said.