LONDON: The balance between supply and demand in the oil market is fragile, Iranian Oil Minister Bijan Zanganeh said on Monday, as he called on crude producers to be wary of troubles caused by U.S. sanctions.

Oil prices are being supported by U.S. sanctions on Iran and Venezuela along with voluntary supply cuts by the Organization of the Petroleum Exporting Countries and other major producers.

"Oil market is in a fragile situation considering the supply and demand balance, so the oil producers should be wary of any trouble in the oil market, especially due to U.S. measures against big oil producers," Zanganeh was quoted as saying by state news agency IRNA upon his arrival in Moscow.

Zanganeh was travelling to Moscow to discuss the oil market with his Russian counterpart Russian Energy Minister Alexander Novak.

"Russia is one of the biggest oil producers in the world, and we are in a situation that we thought it is necessary to discuss the oil market with our Russian friends," Zanganeh said.

The U.S. reimposed sanctions on Tehran in November after pulling out of a 2015 nuclear accord between Iran and six world powers. Those sanctions have already halved Iranian oil exports.

The United States is likely to renew waivers to sanctions for most countries buying Iranian crude, including the biggest buyers China and India, in exchange for pledges to cut combined imports to below 1 million barrels per day.

U.S. President Donald Trump eventually aims to halt Iranian oil exports and thereby choke off Tehran's main source of revenue. Washington is pressuring Iran to curtail its nuclear programme and stop backing militant proxies across the Middle East.