OPEC pledged to provide "adequate, timely and sufficient" oil supplies to the market and voiced concern about global climate change.
In a final declaration on Sunday from a summit meeting of its heads of state, the organisation also said it recognised the importance of energy in fighting poverty, but made no mention of the weak dollar.
"We affirm our commitment ... to continue providing adequate, timely and sufficient oil to the world market," said the statement issued after two-day summit in the Saudi capital Riyadh.
"We recognise that energy is essential for poverty eradication," it said, calling on consuming nations to pursue fair international trade practices. "Eradication of poverty should be the overriding global priority.
OPEC's backing for the fight against global warming came as Kuwait pledged $150 million towards research into energy and Saudi Arabia, the world's top oil exporter, said it would give $300 million for environmental research.
Other leaders were reluctant to make similar promises. "We are not committing anything. We don't know what the proposal is," Algerian Energy Minister Chakib Khelil said. "As far as I am aware, nobody else has committed anything either."
Ecuador's leftist President Rafael Correa said on Sunday the world's richest nations should pay for programmes to protect the environment in the world's poorest countries.
He proposed a special tax on oil-consuming nations to pay for environmental protection measures elsewhere, with OPEC coordinating spending.
"It annoys us a bit, all this moralising 'don't cut down your trees' from the first world, when they've already done it," Correa told a press conference in Riyadh.
"If Europe wants to breathe pure air from Amazon countries then the Amazon countries shouldn't have to pay for it."
Tensions over Iran
Venezuelan President Hugo Chavez on Saturday warned that oil prices, already near $100 per barrel, could double if the United States attacks his ally Iran over its disputed nuclear programme.
"If the United States is crazy enough to attack Iran or commit aggression against Venezuela ... oil would not be $100 but $200," Chavez told heads of state including Iranian President Mahmoud Ahmadinejad.
Fears the United States or its ally Israel could attack Iran, which Washington says is covertly seeking to develop atomic weapons, have helped drive world oil prices to record levels. Tehran denies the charge.
Soaring prices have prompted calls by consumer nations for the exporters' group to pump more crude, but OPEC oil ministers said this week any decision on raising output will be left to a meeting in Abu Dhabi on Dec. 5.
Correa told the conference on Sunday he favoured pricing oil in a currency stronger than the dollar. The U.S. currency's drop in the value against other major currencies has helped fuel oil's rally to $98.62 last week, but has also cut the purchasing power of the Organization of the Petroleum Exporting Countries.
More Active Geopolitical Role
On Friday, Saudi Arabia steered the group towards rebuffing an attempt by Iran and Venezuela to highlight concern over dollar weakness in the summit communique.
Analysts say Saudi King Abdullah, a close U.S. ally and, as OPEC's "swing producer," veteran guarantor of crude to the United States, was keen to keep populists Chavez and Ahmadinejad from grabbing the summit limelight with anti-U.S. rhetoric.
The octogenarian leader sat stony-faced throughout Chavez's 25-minute speech on Saturday and was heard joking to the Venezuelan president afterwards: "You went on a bit!"
Addressing leaders assembled in an opulent hall with crystal chandeliers and toilet accessories fitted in gold leaf, self-styled socialist revolutionary Chavez said OPEC "must stand up and act as a vanguard against poverty in the world.
"OPEC should be a more active geopolitical agent and demand more respect for our countries ... and ask powerful nations to stop threatening OPEC," he said.