Oil prices fell more than 1 per cent on Tuesday, with benchmark Brent crude slipping below $70 per barrel and US crude under $60, after US President Donald Trump put pressure on OPEC not to cut supply to prop up the market.
The US dollar hovered near 16-month highs, making oil more expensive for importers using other currencies.
Brent was down $1.03 at $69.09 per barrel by 0900 GMT.
US light crude was $1.00 lower at $58.93. Both benchmarks are down 20 per cent since peaking at four-year highs in early October.