Russia and Saudi Arabia said they expect OPEC and non-OPEC producers to reach an agreement on Saturday to curtail oil output and prop up prices in the first such joint move since 2001.
"We have a deal already. We are just putting the final touches. Everything is good!" Khalid al-Falih, energy minister of OPEC's de facto leader and top oil exporter Saudi Arabia, told reporters.
Russian Energy Minister Alexander Novak, speaking as he joined a breakfast with OPEC and non-OPEC ministers in Vienna, said: "I don't see such risks (of a deal failing)."
The Organization of the Petroleum Exporting Countries will meet producers from outside the group later in the day, hoping non-OPEC will commit to cutting 600,000 barrels per day after its own members agreed a reduction of 1.2 million barrels per day last week.
OPEC Secretary-General Mohammed Barkindo said he expected 12 non-OPEC countries to sign a declaration with the organisation and fully contribute to cuts of 600,000 bpd or more.
"This is a very historic meeting ... This will boost the global economy and will help some OECD countries to reach their inflation targets," Barkindo told reporters, referring to the Organisation for Economic Cooperation and Development, which groups most of the world's richest economies.