US State Department spokeswoman Heather Nauwert said on Thursday deputy commander of Iran-allied IMIS Militia, Abu Mehdi al-Mohandis is a "terrorist", the Baghdad Post reported.
"This person is a terrorist and that's all we can say right now," she said to reporters.
Al-Muhandis, whose real name is Jamal Jaafar Ibrahim, is wanted for trial in US and Kuwait for terror attacks.
He was the mastermind for required for the bombing the US and French embassies in Kuwait in December 1983, killing six people and wounding 80 others including Western nationals.
Regarding the continued Iraqi aggression against Kurds in Kirkuk and other disputed areas, Nauwert reiterated State Secretary Rex Tillerson's calls for both sides to reach an agreement to ceasefire.
"We demand that Iraqi PM Haider Abadi and Kurdistan Region President Masoud Barzani begin the dialogue and set a timetable for that," she said.
"If Kurds ask us to participate in the dialogue, we will definitely participate, but we have not yet received requests to mediate in the talks," she said.