Iraq’s Prime Minister Haider al-Abadi has assigned Deputy Governor of Kirkuk Rakan Saeed al-Jobouri to run the city until a new governor is chosen in accordance with the local municipals’ elections, parliamentarian Jasim Mohamed Jafaar told al-Sumaria TV on Monday.

Al-Jobouri is the first Arab governor in Kirkuk since 2003, according to Iraqi media reports.

“According to local elections’ law, the deputy governor of Kirkuk is acting as the city’s new governor succeeding Najmaldin Karim who was dismissed upon a decision taken by the Iraqi parliament late September,” Jafaar told Al-Sumaria.

He added that “Jobouri should remain in charge until a new governor is assigned by the prime minister or a new military ruler takes control of the city upon orders from the federal government in Baghdad.”

The appointment comes as Iraqi forces have gained control of Kirkuk’s airport and main military base as well as other strategic locations in the oil-rich province from Kurdish fighters.

Iraqi sources declared on Monday that the country’s security forces have gained full control of the airport and the K1 airbase, the largest one in Kirkuk.

The operation is carried out to take key areas in the disputed region following last month’s referendum held for possible secession of the Iraqi Kurdistan.

Meanwhile, some officials from the Patriotic Union of Kurdistan (PUK) have refrained from fighting with Kurdish forces against Iraqi central government. KRG President Masoud Barzani’s party has condemned the PUK officials’ move as a betrayal, saying Jalal Talabani’s party has committed a great and historic treason against Kurdistan.

In reaction to the developments, the US Department of Defence has urged Iraqi and Kurdistan Regional Government (KRG) forces Sunday to “avoid escalatory actions” and to turn to dialogue to defuse tensions and resolve their differences.

“We oppose violence from any party, and urge against destabilizing actions that distract from the fight against ISIS and further undermine Iraq’s stability,” Pentagon spokeswoman Laura Seal said when asked about an Iraqi state TV report that Iraqi forces had taken control of parts of the oil-rich Kirkuk region without opposition from Peshmerga fighters.

“We continue to support a unified Iraq,” she said. “Despite the Kurdistan Regional Government’s unfortunate decision to pursue a unilateral referendum, dialogue remains the best option to defuse ongoing tensions and longstanding issues, in accordance with the Iraqi constitution.”

She also called on “all actors” in the region to focus on the common threat of ISIS and avoid stoking tensions among the Iraqi people. Iraqi and Peshmerga forces have both been trained and armed by the United States.

Iraqi officials have declared that the Iraqi Counter Terrorism Service has deployed its forces in K1 airbase, the major and biggest military base of the oil-rich city of Kirkuk.

The Iraqi state TV earlier reported that the central government forces have taken control of “vast areas” in the region of Kirkuk, including oilfields west of the city, in the early hours of Monday.

Iraqi Prime Minister Haider al-Abadi ordered security forces “to impose security in Kirkuk in cooperation with the population of the city and the Peshmerga”, the TV reports said.

“Iraq’s Counter Terrorism Service, the 9th armored division and Federal Police have taken control of vast areas of Kirkuk without confrontations,” it said, adding that oilfields and Kurdish military positions were captured.

However, a Kurdistan Regional Government security official denied that Iraqi forces were able to get closer to the city.

The most serious clash happened south of Kirkuk, an exchange of artillery fire between the Peshmerga and Iraq’s Popular Mobilization Forces, also known as Hashd al-Shaabi, the KRG official said.

There were clashes between Kurdish and Shiite Turkmen groups in another city, Tuz Khormatu, about 75 km (50 miles) south of Kirkuk, but no casualties were reported.

“Iraqi forces and Popular Mobilization Forces are now advancing from Taza, south of Kirkuk, in a major operation,” the KRG Security Council said in a statement around midnight.

Neither side provided a toll of casualties.

The Iraqi forces’ operation in the region of Kirkuk followed meetings held on Sunday by the Iraqi government in Baghdad and the Kurdish leadership in the town of Dokan.

Earlier reports said that KRG President Masoud Barzani and top Kurdish officials who met in Dokan rejected the Iraqi government’s demand that it cancel the outcome of the independence referendum as a precondition for talks to resolve the dispute.

Kirkuk, a city of more than a million people with a large Kurdish community, lies just outside KRG territory, but Peshmerga forces were stationed there in 2014 when Iraqi security forces collapsed in the face of ISIS onslaught.

Iraq’s semi-autonomous Kurdish region held a referendum for independence on September 25 amid regional and international opposition.