Saudi Arabia and non-OPEC Russia have said a production increase of about 1 million barrels per day (bpd.) or around 1 per cent of global supply had become a near-consensus proposal for the group and its allies.
Saudi Energy Minister Khalid al-Falih had earlier signalled a compromise could be in the works.
"I am sure we will come to consensus, and we will look back at this meeting as being equally important to the one we had in late 2016 when we chose to take that first action we took as 24 countries of restricting supply to bring stability back to the market", he added.
The U.S. has reimposed sanctions, but it doesn't want its consumers to pay the price for that at the pump. "The already fragile world economic growth will be at threat if oil prices persist at these levels".
Friday's meeting could be a tense affair.
U.S. West Texas Intermediate and international-benchmark Brent crude oil settled sharply higher as investors continued to position themselves ahead of a key meeting of OPEC producers that may decide to increase global output. The final wording of the deal is still under discussion, the delegate said.
This of course is due to the fact that the increase here is going to be done on a pro-rata basis and even if they stick to a 100% compliance, not many countries have the spare capacity to step up in order for the cartel to reach the 1 million bpd mark in total.
That means the country has little to gain from a deal to raise OPEC output, unlike top oil exporter Saudi Arabia.
Oil prices rose in early Asian trading on Wednesday, supported by a drop in US commercial crude inventories reported by the American Petroleum Institute (API).
Trump's involvement in pressing for OPEC to act - which in addition to his tweets include a behind-the-scenes request for a 1 million-barrel-a-day supply hike - could make it hard for Tehran to accept a compromise. However, it exports below seven million barrels daily. The two top crude oil suppliers to China are Russian Federation and Saudi Arabia, with Russian Federation beating the Saudis for the top spot in each of the past 13 months.
If the existing deal is retained and Saudi Arabia felt there was a need to add more oil, Riyadh could still increase production unilaterally, as it did after a meeting in June 2011 ended with no decision.
In a night of drama in Vienna, the Joint Ministerial Monitoring Committee, which recommends policy to the group, reached an agreement despite Bijan Zanganeh, the Iranian oil minister, walking out of the meeting and predicting Opec won't reach a final deal when it meets formally on Friday.
Falih has warned the world could face a supply deficit of up to 1.8 million bpd.in the second half of 2018 and that OPEC's responsibility was to address consumers' worries. Off-topic, inappropriate or insulting comments will be removed.