"No, I am not confident" about the chances of a deal, Saudi oil minister Khalid Al-Falih told reporters after a long day of negotiations at OPEC's headquarters in Vienna.
However, OPEC and its non-cartel members -- who account for around half of global output -- agree on one thing: a glut on the market has led to oil prices falling by more than 30 per cent in the space of two months.
However, the major players among the oil giants all have their own reasons to look to others to act.
For Russia, which leads the non-member countries in the so-called OPEC+ alliance, "it's much more difficult to cut than for other countries, because of our climatic conditions," Russian Energy Minister Alexander Novak said on Thursday in Saint Petersburg.
Saudi Arabia, meanwhile, has to bear in mind pressure from the US, after President Donald Trump demanded in a tweet on Wednesday that OPEC not boost prices.
In addition, the kingdom's diplomatic position has been weakened by the furore over the killing of journalist Jamal Khashoggi.
Though al-Falih insisted that "we don't need permission from anyone to cut" production, the figure of a million barrels put forward by Saudi Arabia was lower than the reduction expected by the markets.
Iran, Saudi Arabia's geopolitical rival and OPEC's third-largest producer, suggested it was in favour of deeper cuts -- while asking to be exempted from them because of the effects of US sanctions targeting its oil sector.
The thorny question of exemptions, which will also be sought by Venezuela and Libya according to the Bloomberg news agency, could be crucial for Friday's talks.
The amount and the timetable of any cuts imposed by Russia will also be a key sticking point.
Iraqi oil minister Thamir Abbas Al Ghadhban said he was still "hopeful" an agreement could be reached during talks on Friday.
However, markets displayed doubts with fresh falls in oil prices sparking a sell-off of stocks by investors.
The price of a barrel of Brent, the European benchmark, sank below the symbolic USD 60 mark because the reduction of around one million barrels floated by Saudi Arabia was below what markets had been expecting.
Analysts say that the details of any agreement will be key in determining what happens next to prices.
"If it's one million (barrels) excluding Iran, then it's in fact 1.2, 1.3, which should be supportive of price," Abhishek Deshpande, an oil analyst at JP Morgan, told AFP.
"But if (the agreement) is including Iran, that's not enough," Deshpande added.
In June, OPEC and its partners agreed to allow for a boost in production by Saudi Arabia and Russia to compensate for the expected losses in production from Iran after the US dramatically withdrew from the Iran nuclear deal in May and vowed to re-impose sanctions.
However, the US then granted temporary waivers to eight allies to allow them to carry on importing Iranian oil, contributing to a plunge in oil prices which wiped out the gains seen since early 2017.
(With inputs from agencies.)