IRAQ said Opec should resist pressure to increase oil supplies, strengthening opposition to Saudi Arabia's plans as the group prepares to meet next week.
Opec's second-biggest producer said supply curbs by the cartel haven't yet achieved their purpose, with oil prices still below the desired level. Its defiance follows similar resistance from Iran and Venezuela, meaning three of the five countries that founded Opec now oppose the Saudi plan.
The US has reportedly asked Saudi Arabia and others to relax output restraints put in place in early 2017 as prices near US$80 a barrel pose a threat to economic growth. The kingdom and partner Russia, which last month proposed increasing supplies later this year without first consulting Opec members, appear to be raising production already.
"Producers from within and outside Opec have not yet reached the goals set," Iraqi Oil Minister Jabbar al-Luaibi said in a statement. Iraq "rejects unilateral decisions made by some producers which do not consult with the rest."
This is setting the scene for a fractious meeting when the Organization of Petroleum Exporting Countries and its partners gather in Vienna on June 22-23. Iran and Venezuela - both subject to US sanctions - have written to fellow Opec members urging unity against American pressure. Both producers stand to lose market share if Saudi Arabia and Russia open the taps.
Iraq faces both technical constraints on boosting supply and a political clash with its Kurdish population that's impeded exports, and so may have little to gain from any Opec agreement to raise production.
"We shouldn't exaggerate the need of the oil market for more oil at the present time, and which could cause great damage to global markets," Mr Jabbar said.
Nevertheless, it's unclear whether Iraq, Iran and Venezuela could do much to block the Saudi-Russian plans. Although Opec's rules require that decisions are made by consensus, there's nothing to stop Saudi Arabia and its Gulf allies from simply raising output in concert with Moscow.
Russia, despite its political connections with Iran and Venezuela, looks like it's in the process of raising supply already. The country pumped 11.09 million barrels a day in the first week of June, according to a person with knowledge of the matter, exceeding its agreed limit of 10.95 million.
Saudi Arabia has enjoyed diplomatic ties with the US for decades, and may be facing strong pressure to temper oil prices as President Donald Trump targets Iran - the kingdom's political rival - with sanctions.
The US hasn't asked Opec to bolster supplies, United Arab Emirates Oil Minister Suhail Al Mazrouei - who this year holds Opec's rotating presidency - told CNN.
Saudi Arabia, Opec's biggest producer, also seems to be restoring halted output, having pumped more than 10 million barrels a day last month for the first time since October, according to a person familiar with the matter.
Saudi Arabian Oil Co, the kingdom's state-run producer, will supply full crude volumes to buyers in Asia in July, according to a person familiar with the situation. Saudi Aramco, as the company is known, earlier this month raised pricing on key crude grades for buyers in Asia to the highest since 2014, giving a sign it sees sufficient demand for its crude in that market. BLOOMBERG