The world's two biggest oil producers Saudi Arabia and Russia say they have agreed to "act together" to stabilise oil prices as they seek to steady the markets.

"The ministers noted the particular importance of constructive dialogue and close cooperation between the largest oil-producing countries with the goal of supporting the stability of the oil market and ensuring a stable level of investment in the long -term," the energy ministers from the two sides said.

Their comments came in a joint statement after a meeting at the G20 summit in China.

"To this end the ministers agreed to act together or in cooperation with other oil producers," the statement said, adding they had agreed to set up a "joint monitoring group" to offer recommendations aimed at preventing price fluctuations.

Russia's Energy Minister Alexander Novak described the announcement as marking a "new era" in cooperation between Russia and Saudi Arabia and insisted that it would have "critical significance" for oil markets, news agency Interfax reported.

But there were few firm details in the announcement, which comes just weeks before Moscow and the Organisation of the Petroleum Exporting Countries (OPEC) meet in Algeria to discuss the crisis.

The globe's major oil producers have been unable to strike a deal on freezing output, due mainly to a dispute between Saudi Arabia and Iran over Tehran's desire to boost levels after the lifting of sanctions.

Russian President Vladimir Putin met Saudi Deputy Crown Prince Mohammed bin Salman on the sidelines of the G20 and said they would work to address a global glut and overproduction that has hammered prices for the past two years.

The oil market has been plagued by a stubborn supply glut that saw prices plunge to near 13-year lows below $US30.00 ($39.55) at the start of 2016.

While it has recovered recently, it is still well off highs above $US100 ($131.84) seen in mid-2014.

AFP