US Secretary of State Rex Tillerson (Photo: AFP/VNA)

US Secretary of State Rex Tillerson said on Friday that the Monday vote and the results lack legitimacy. The US continues to support a united, federal, democratic and prosperous Iraq. The United States asks all parties, including Iraq's neighbors, to reject unilateral actions and the use of force, he added.

The top US diplomat said Washington was concerned about the potential negative consequences of this unilateral step, and urged Iraqi Kurdish authorities to respect the constitutionally-mandated role of the central government.