They are being joined by some non-member oil producing countries, notably Russian Federation.
Five OPEC delegates told Reuters news agency the group was waiting for news from Russian Federation, as Energy Minister Alexander Novak had flown back from Vienna on Wednesday for a possible meeting with President Vladimir Putin.
Mr Novak will return to Vienna on Friday for the OPEC and allies meeting. "I am optimistic. There will be a deal, but it is unclear how much Opec and how much non-Opec will contribute". A delegate from another country said some members believe a smaller reduction would be adequate.
The current 1.8 million barrels per day production cut will expire in December. But, as mentioned, a total of 1.3 million bpd cut could nonetheless be agreed upon from the OPEC+ group.
When asked if the Saudis had permission from Trump to cut production, Al-Falih replied: "I don't need permission from any foreign governments".
The Organisation of the Petroleum Exporting Countries (OPEC) is expected to agree to cut oil production at a meeting aimed at supporting oil prices.
The United States energy industry continued to soar to life under President Trump and the GOP-controlled Senate this week; becoming a "net exporter of oil" for the first time in over 75 years.
Oil prices were pressured by a weekly report from the American Petroleum Institute (API) that said U.S. crude inventories rose by 5.4 million barrels in the week to November 30, to 448 million barrels, in a sign that U.S. oil markets are in a growing glut.
The EIA said the U.S. has been a net oil importer in weekly data going back to 1991 and monthly data starting in 1973.
India vs Australia: India is 'smelling blood' concedes Australian coach Justin Langer
"If they bowl, just keep the pressure on and Josh Hazlewood in particular, to me, is a key part of that". In essence, BCCI has indicated that India will be going with six batters.
Brent oil prices, which lost 30 per cent of their value last month after climbing as high as $86 per barrel in October, needed a harsher cut of more than one million bpd to recoup some of the losses, according to analysts.
"Given the economic sanctions being reimposed by the United States, the Islamic republic "(won't) join any agreement for cutting production because of the special situation Iran faces", Zanganeh said.
However, when oil producers realized the sanctions fell far short of what had been expected, fears of oversupply followed.
Mr Trump tweeted on Wednesday: "Hopefully OPEC will be keeping oil flows as is, not restricted".
Crude prices have been falling since October because major producers - including the USA - are pumping oil at high rates, and due to fears that weaker economic growth could dampen energy demand. Trump said on Twitter.
So far, Trump has supported Saudi Arabia's version of the story, which exonerates Crown Prince Mohammed bin Salman of any involvement in the murder, despite USA intelligence agencies allegedly telling Trump the prince was involved.
"OPEC is an independent organization, not a part of the US Department of Energy to take orders from Washington", said Zangeneh on Wednesday.
"The big unknown is how President Trump will react to any production cuts", said analysts at ING. Only the headline has been changed.