The oil ministers of Iraq and Iran both told CNBC on Wednesday that they're ready to back a deal to extend OPEC-led production cuts through the first quarter of 2018. OPEC is meeting in Vienna to discuss rolling over its six-month deal with 11 other exporters to remove 1.8 million barrels a day from the oil market in order to shrink global crude stockpiles. Consensus has formed in recent weeks around a nine-month extension, along the lines of a plan agreed to last week by Saudi Arabia and Russia. Iraq and Iran are critical because they are the second- and third-biggest producers, respectively, in the 13-member cartel — and both have presented obstacles to getting a deal done in the past. On Wednesday, Iraqi Oil Minister Jabbar al-Luaibi said Iraq is "very happy" to go along with the extension, but he cast doubt on the odds of OPEC agreeing to deeper production cuts — which some analysts now believe is necessary.

Jabbar al-Luaibi, Iraq's oil minister, arrives for the 171st Organization of Petroleum Exporting Countries (OPEC) meeting in Vienna, Austria, on Wednesday, Nov. 30, 2016. Akos Stiller | Bloomberg | Getty Images

"I don't think so. It's only the freeze we are talking about. We will continue with the current cuts," Luaibi told CNBC in Vienna. "We will continue to discuss this." Asked whether Iraq plans to improve its compliance with the deal, he said, "definitely." As of April, Baghdad had still not achieved its promised output reductions of 210,000 barrels a day from the October reference level, according to figures in OPEC's monthly report. Earlier this week, Luaibi said Iraq was now producing at its quota. Iranian Oil Minister Bijan Zanganeh said either a six- or nine-month extension would be acceptable. "We think, based on the consultations we have had and the reports we have received, it's a unanimous idea to continue the cut we decided in December," he told CNBC.