As OPEC ministers arrive in Vienna ahead of the summit, U.S. President Donald Trump has been pressuring OPEC to cut crude oil prices.
But OPEC and Russia are moving closer to reducing output.
Saudi Arabia has indicated a need for sharp producton cuts.
Oman's Oil Minister Mohammed bin Hamad Al-Rumhy said Russia also agrees on the need for a reduction.
SOUNDBITE: OMAN OIL MINISTER, MOHAMMED BIN HAMAD AL-RUMHI, (ENGLISH) SAYING: "We call it a reduction." SOUNDBITE: JOURNALIST ASKING: "A reduction of how much?" SOUNDBITE: OMAN OIL MINISTER, MOHAMMED BIN HAMAD AL-RUMHI, (ENGLISH) SAYING: "Look this is an uncharted territory." He said the ministerial committee is still discussing exact volumes.
Accounting for potential OPEC production cuts, Wells Fargo Investment Institute forecasts that next year, U.S. crude prices will rebound to up to $70 a barrel.
That would be a sharp reversal of this year's steep slide.
On Wednesday, U.S. crude prices eased to around $52 a barrel.
According to a report by Reuters, on Saturday, Iranian Oil Minister Bijan Zanganeh praised OPEC for what he said was the producer group's ability to reach agreement despite intense internal political..