Iraq's autonomous Kurdish region announced on Tuesday that it made over $3.94 billion last year from direct oil export sales that the country's federal government considers illegal.

The region is facing a financial crisis despite the substantial oil revenues, and has announced that its employees will not be paid their full salaries until further notice and that months of wage arrears will be considered loans to the government.

The Kurdistan region "achieved revenues of US $3,949,697,778" from June 24 to December 31, "a substantial increase on the amount received from Baghdad during the first half of the year," it said in a statement.

Baghdad, which has like Kurdistan been hit hard by plunging oil prices, paid the region $1,986,742,842 from January 1 to June 23, the statement said.

Iraqi Kurdistan has been independently exporting and selling crude from northern territory it controls via Turkey since a deal with Baghdad on oil and revenue-sharing collapsed last year.

On Monday, Iraqi Prime Minister Haider al-Abadi said he would be willing to pay the salaries of regional government employees if it ceases independent exports.

"Give us the oil and I will give every employee in Kurdistan (their) salary," Abadi said in an interview with state television.

Kurdistan deputy prime minister Qubad Talabani responded on his Facebook page that if Baghdad did in fact pay the salaries, an "agreement with them would be easy and natural."

But the power to make such an agreement lies largely with the region's de facto president Massud Barzani and his Kurdistan Democratic Party, and he has not indicated that he would accept.