Turkey said Friday it has begun exporting oil supplies from Iraqi Kurdistan to international markets, a move that could exacerbate strained tensions between Baghdad and Kurds.
Energy Minister Taner Yildiz told reporters that shipments of Iraqi oil from Turkey's Mediterranean port of Ceyhan began Thursday evening.
"It's Iraq that makes sales and possesses the oil and it's again Iraq that will govern the future sales," said Yildiz.
The exports via Turkey came in defiance of Baghdad which claims its oil ministry must approve all sales.
Iraq has some of the world's largest deposits of oil and gas, and the central government in Baghdad insists it has the sole right to develop and export the country's natural resources.
Since the US-led invasion in 2003, Baghdad has been at loggerheads with the energy-rich autonomous northern Kurdish region, which has sought to sign deals with foreign firms and export without the consent of the central government.
The exports through Turkey could raise tensions between the Kurds and Baghdad after the April 30 elections in which the country's Shiite Prime Minister Nuri al-Maliki emerged the biggest winner.
The United States voiced concerns on Thursday that the move could destabilise Iraq.
"Our position has long been that we don't support exports without the appropriate approval of the federal Iraqi government, and certainly we do have concerns about the impact of those continuing," US State Department spokeswoman Jen Psaki told a daily press briefing in Washington.
"Our most immediate concern is for Iraq's stability," she said.
"Iraq is facing a difficult situation. We've been clear that it's important for all sides to take actions to help the country pull together and avoid actions that might further exacerbate divisions and tensions".
The latest development also risks harming Ankara's relations with Baghdad.
Last year, Turkey offered to serve as an independent intermediary by having Iraq's oil revenue deposited into an escrow account at a Turkish state bank.
In the past Turkey refused to engage in official contacts with Iraqi Kurds, fearing the establishment of a Kurdish state there could embolden its own Kurdish minority, which had waged a long separatist campaign.
But as Turkey's economy has boomed, and its thirst for energy grown, Prime Minister Recep Tayyip Erdogan's government has moved to forge ties with Iraqi Kurds.
Erdogan has even referred to the autonomous region in northern Iraq as "Kurdistan", a word long taboo among politicians in Turkey.