BAGHDAD- Russian Energy Minister Alexander Novak did not discuss operations by Russian oil companies in Iraq's Kurdistan region with the Iraqi prime minister or oil minister during his trip to Iraq, the Iraqi oil ministry said on Thursday.

"At a time when the oil ministry welcomes all international oil companies to invest and work in Iraq, it also affirms that oil is a sovereign resource, and therefore all contracts ... should be signed with the federal government and the oil ministry," it said in a statement.

"Anything contrary to that means these entities are liable for all the consequences, legal and financial responsibilities, and damages resulting from that."

Novak had tweeted on Wednesday that the government of Iraq had no objections regarding operations by Russian oil companies in the semi-autonomous Kurdistan region of northern Iraq.

(Reporting by Ahmed Aboulenein; Editing by Mark Potter) ((ahmed.aboulenein@thomsonreuters.com; +964 790 191 7021; Reuters Messaging: ahmed.aboulenein.thomsonreuters.com@reuters.net))