An employee stands at the Hammar Mushrif new Degassing Station Facilities site inside the Zubair oil and gas field, north of the southern Iraqi province of Basra on May 9, 2018.

Developing countries' oil and gas income could fall to their lowest levels in more than two decades if current energy market conditions persist, the IEA and OPEC have warned in a rare joint statement.

IEA Executive Director Fatih Birol and OPEC Secretary General Mohammed Barkindo expressed "deep concerns" about the coronavirus pandemic on Monday, warning it could have "potentially far-reaching economic and social consequences."

Birol and Barkindo said they expect developing countries to see their oil and gas income fall by 50% to 85% in 2020.

They singled out public sector spending in vital areas such as health care and education as being especially vulnerable.

International benchmark Brent crude traded at $29.91 Tuesday morning, down around 0.7%, while U.S. West Texas Intermediate (WTI) stood at $28.98, more than 1% higher.

Oil prices slid 10% in the previous session, as the coronavirus continues to spread worldwide and amid an ongoing price war between OPEC kingpin Saudi Arabia and non-OPEC leader Russia.

Crude futures have more than halved since climbing to a peak in January.