The United States does not recognize the results of a referendum on independence held in Iraq's autonomous Kurdish region on September 25.
U.S. Secretary of State Rex Tillerson issued a statement on September 29 saying that the referendum results "lack legitimacy" and expressing U.S. support for "a united, federal, democratic, and prosperous Iraq."
Tillerson also called on "all parties, including Iraq's neighbors, to reject unilateral actions and the use of force."
Iraqi Kurds overwhelmingly voted in favor of independence in the referendum.
Baghdad responded by cutting the region's direct air links with the outside world.
Also on September 29, French President Emmanuel Macron offered to help mediate between Baghdad and the Kurdish region, also calling for all parties to avoid further escalations of tensions.
Macron made the offer during a telephone conversation with Iraqi Prime Minister Haidar al-Abadi.
With reporting by Reuters