"The ill-advised Kurdish referendum has created tension, but we appear to be on-track to resolve this constitutionally, thanks largely to Prime Minister Abadi's patience," Mattis said during NATO meetings in Brussels on Thursday.
The Kurdistan Region held a referendum on September 25 on independence from Iraq. No declaration of independence was ever announced. A court in Baghdad decided on Monday that the Iraqi constitution "does not allow any community [region] to separate."
The Kurdistan Regional Government has not officially responded to the court ruling, but previously offered to freeze the results of the referendum. Abadi wants it "canceled."
The United States was instrumental in drafting the 2005 Iraqi constitution. However, parts of the constitution, like the creation of a Supreme Court to rule on constitutional law, have not been implemented. Additionally, several articles which settle oil sharing and the status of disputed areas like Kirkuk remain unsettled and ignored.
Iraqi forces and Iran-backed militias clashed with Kurdish forces in October after Abadi ordered the imposition of federal control over disputed areas claimed by both Baghdad and Erbil.
Former Kurdistan Region President Masoud Barzani and Iraqi Vice President Osama al-Nujaifi, a Sunni, have said the United States and the United Kingdom were aware of the October 15 plans to forcibly impose federal authority.
The United States has continuously praised the nearly 2,000 Kurdish Peshmerga who died and the 10,000 who were injured fighting ISIS.
"Arab and Kurdish, Sunni and Shiite forces under Prime Minister Abadi's leadership have worked together with unprecedented levels of cooperation,” said Mattis, a retired general.
The Peshmerga and the Iraqi army, who have fought bitter wars in the past, formed a joint command and coordinated in the battle to liberate Mosul from ISIS. That cooperation ended when Iraqi forces advanced against the Peshmerga in October. Now, the two are engaged in security-level talks to reach a lasting ceasefire and agreement on control of the disputed areas and international borders.
Abadi faces re-election in May and is seen as the preferred US pick.
