Oil prices have continued to tumble after US President Donald Trump warned Opec against cutting production.

The oil cartel has also cut its world oil demand growth for 2019 due to uncertainties around global economic development.

Brent crude continued its slide below $70 per barrel trading at $68.81 this afternoon, almost two per cent down for the day, while WTI crude also dropped two per cent to $58.75.

Saudi Arabia announced on Monday it would cut oil production in December by 500,000 barrels per day in a bid to put an end to a 20 per cent drop in oil prices over the past two weeks.

Prices had surged ahead of US sanctions on Iran but have subsequently fallen after the sanctions proved less severe than expected.

An official from Kuwait also indicated that more oil producers could follow the Saudis in cutting production.

But Donald Trump urged the major oil exporters not to cut production.

Taking to social media, Trump said: “Hopefully Saudi Arabia and Opec will not be cutting oil production.

“Oil prices should be much lower based on supply.”

Just hours after the President's comments, the cartel cut its world oil demand growth forecasts for 2019 in its monthly report for November.

It said growth was now pegged at 1.29m barrels per day, 70,000 barrels per day lower than its prediction last month.

Opec said the downgrade was due to uncertainties around global economic development.