Iraq’s government warned Turkey this week that it needs Baghdad’s permission to build oil and natural gas pipelines from the Kurdish autonomous region in the north.

Turkey made a deal with the Kurdistan Regional Government to pipe oil and gas directly from Kurdistan in the next twelve months, without the approval of the central government in Baghdad. The Kurds also plan to independently barter crude oil with refined petroleum products.

Last year, Kurdistan signed an oil deal with the American supermajor ExxonMobil over Baghdad’s objections.

In their conflict with the central government, Ankara has sided with the Kurds even as it battles a Kurdish insurgency within its own borders. More than half of Turkey’s $12 billion trade with Iraq last year was with Kurdistan.

Tensions between Ankara and Baghdad have mounted as a result. Turkish prime minister Recep Tayyip Erdoğan accused his Iraqi counterpart last month of exacerbating the sectarian divide between Shia, Sunnis and Kurds for political gain which prompted Nouri al-Maliki to brand Turkey a “hostile state.”

Erdoğan also met with Iraq’s fugitive Sunni vice president Tariq al-Hashimi who fled to Kurdistan after Maliki’s government accused him of leading death squads against Shiites. Hashimi, who denies the charges, has since been offered refuge in Turkey.

The Turks worry that the sectarian violence in Iraq and Syria will lead to a wider conflict between Shia and Sunni Muslims. Maliki’s rapprochement with Shiite Iran is therefore regarded with apprehension in most Sunni states.

The Kurds share Turkey’s concern. Masoud Barzani, the president of Iraqi Kurdistan, suggested in April that his region may break away from Baghdad unless Maliki changed his ways. “What threatens the unity of Iraq is dictatorship and authoritarian rule,” he said.