The Iraqi government said Wednesday it was troubled by the alleged sale of crude oil from parts of the country under the control of a Sunni terrorist group.

The Sunni-led Islamic State has taken control over parts of northwestern Iraq. Last week, the U.N. Security Council passed a resolution condemning the use of oil as a source of finance for a group known also as the Islamic State in Iraq and the Levant.

The Iraqi Ministry of Oil said Wednesday it was calling on U.N. member states to take action to prevent the export of smuggled crude oil into territories they control.

"The Ministry of Oil is troubled by reports that crude oil from fields currently under the control of ISIL is being smuggled to export markets, generating revenues for this terrorist organization," it said in a statement.

The ministry said the only entity authorized to sell crude oil on the international market was the State Organization for Marketing of Oil.

"International purchasers and other market participants should be aware that any oil exports made without the authorization of the Ministry of Oil may contain crude oil originating from fields under the control of ISIL," the ministry warned.

The ministry made no direct reference to ongoing legal disputes with the semi-autonomous Kurdistan Regional Government, which has worked to sell crude oil produced from its territory on the international market since May.