The Organization of the Petroleum Exporting Countries meets on Friday to set output policy amid calls from U.S. President Donald Trump and China to cool down oil prices and support the global economy by producing more crude.
OPEC's de facto leader, Saudi Arabia, and non-member Russia have proposed gradually relaxing production cuts - in place since the start of 2017 - while OPEC members Iran, Iraq, Venezuela and Algeria have opposed such a move.
"I don’t believe at this meeting we can reach agreement. OPEC is not the organisation to receive instruction from President Trump ... OPEC is not part of the Department of Energy of the United States," Iran's oil minister Bijan Zanganeh told reporters after arriving in Vienna, where OPEC is headquartered.
Zanganeh said he would leave Vienna on Friday before OPEC holds talks with non-OPEC producers the next day and added a recent rise in oil prices was mainly the fault of Washington, which imposed new sanctions on OPEC members Iran and Venezuela.
Trump has called on OPEC to raise output, and Saudi Arabia and Russia said in recent weeks the world needed more oil.
"Oil demand usually grows at the steepest pace in the third quarter ... We could face a deficit if we don't take measures," Russian Energy Minister Alexander Novak said on Tuesday. "In our view, this could lead to market overheating."
Novak said Russia wanted OPEC and non-OPEC to raise output by 1.5 million barrels per day (bpd), effectively wiping out existing production cuts of 1.8 million bpd that have helped rebalance the market in the past 18 months and lifted oil prices to $75 per barrel from as low as $27 in 2016.
In addition to Iran, OPEC members Iraq, Venezuela and Algeria said they opposed a production increase despite supply outages in countries such as Libya and Venezuela.
Demand growth has surprised market watchers on the upside in the past two years, with annual increases exceeding 1.5 percent. Global oil consumption is expected to hit 100 million bpd next year. [IEA/M]
Novak said that if a decision were taken this week to raise output, OPEC and its allies could meet again in September to review the impact and fine-tune production policy.
Iraq and Iran have said they would oppose output increases on the grounds that such moves would breach previous agreements to maintain cuts until the year-end.
Both countries would struggle to increase output. Iran faces renewed U.S. sanctions that will impact its oil industry and Iraq has production constraints.
Two OPEC sources told Reuters that even Saudi Arabia's Gulf allies Kuwait and Oman were against big, immediate increases in output.
One OPEC source said the Saudi-Russian proposal of a 1.5-million-bpd increase was "just a tactic" aimed at persuading fellow members to compromise on a smaller rise of around 0.5-0.7 million bpd.
Saudi Arabia and its Gulf allies have the capacity to raise output. Russia has also said that limiting supply for too long could encourage unacceptably high output growth from the United States, which is not part of the production agreement.
On Tuesday, the head of Russia's second-largest oil firm Lukoil, Vagit Alekperov, said global production cuts should be halved and that Lukoil could restore its oil output levels within two to three months.
Commerzbank commodities analyst Carsten Fritsch said that given big differences in the positions of OPEC members, the Friday meeting was likely to be tough.
"Unanimity is needed for any OPEC decision. This recalls the June 2011 meeting, when OPEC was unable to agree on an increase in production to compensate for the outages ... in Libya," Fritsch said.
"That meeting ended without any joint declaration. The then Saudi Oil Minister Ali al-Naimi described it as the worst OPEC meeting of all time."
Adding to the tensions, Iran and Venezuela continued to insist that OPEC on Friday debate U.S. sanctions against the two countries, but the organisation's secretariat has rejected their requests, according to letters seen by Reuters.
(Additional reporting by Ahmad Ghaddar, Shadia Nasralla, Vladimir Soldatkin and Ernest Scheyder; Writing by Dmitry Zhdannikov; Editing by Dale Hudson)
By Alex Lawler, Rania El Gamal and Polina Nikolskaya