The Kurdish Regional Government (KRG) in northern Iraq has suspended oil exports to neighboring Iran.
In a statement, the KRG's Ministry of Finance and Economy ordered border crossings not to allow the passage of oil tankers into Iran.
The decision was implemented in customs gates as of Friday evening, stopping the movement of hundreds of trucks carrying oil through the border.
The ministry, however, did not specify a reason for the move. It remains unclear whether the suspension is linked to U.S. sanctions on Iran.
In a press conference on Jan. 3, President Donald Trump had voiced discontent over KRG's oil sales to Iran.
According to Organization of the Petroleum Exporting Countries (OPEC) figures, Iraq is the second largest oil exporter after Saudi Arabia with a daily volume of 4.7 million barrels per day. The KRG's production constitutes roughly one-tenth of Iraq's daily production at 420,000 barrels per day, according to an earlier statement of Iraqi Oil Minister Samir Gadban.
Last month, Iranian Foreign Minister Jawad Zarif visited Iraq and the northern region, where he said "no sanctions will affect relations between Baghdad and Tehran."
The trade exchange between Iraq and Iran stands at $12 billion, while officials say the two sides will work to increase the figure to $20 billion annually.
In January, the U.S. State Department announced a 90-day exemption to allow Iraq to continue payments for electricity and gas imports from Iran.
In August 2018, the U.S. re-imposed the first round of economic sanctions on Iran, which mainly target the country's banking sector.
In November of the same year, Washington imposed a second round of sanctions, targeting Iran's energy sector.