A panel of energy ministers representing the Organization of the Petroleum Exporting Countries (OPEC) and non-OPEC producers led by Russia recommended a deeper oil output cut on Thursday.
Saudi Energy Minister Prince Abdulaziz bin Salman said OPEC could not say it had an agreement until it met with non-OPEC producers on Friday.
The oil producers agreed to cut output by an extra 500,000 barrels a day in the first quarter of 2020 but stopped short of pledging action beyond March, Russian Energy Minister Alexander Novak said.
The countries involved pump over 40 percent of the world's oil, and their new combined cuts amount to 1.7 million bpd or 1.7 percent of global production.
OPEC+ has agreed to voluntary reduce supply since 2017 to counter booming output from the shale fields of the United States, which has become the world's biggest producer and is not taking part in cuts.