Oil prices fell further today, with Brent dropping below $55 a barrel, after top exporter Saudi Arabia said it would only consider cutting output if other producers outside OPEC did so too.

The strengthening of the dollar further weighed on prices.

Brent crude oil futures  were trading at $54.70 a barrel at 9:33 a.m., down 62 cents. U.S. WTI crude was down 87 cents at $45.70 a barrel.

Saudi Arabia reiterated its decision to keep production unchanged and ride out a market slump, which has roughly halved prices since June.

"We repeat that, as for prices, the market determines it," Saudi oil minister Ali al-Naimi said on Sunday, adding that Saudi Arabia would only consider output cuts in cooperation with non-OPEC producers.

Analysts at Barclays forecast on Monday that if OPEC production held near current levels of near 30 million barrels per day (bpd), the market surplus would expand from 0.9 million bpd to 1.3 million bpd.

Oil prices have see-sawed, weighed down by concerns of oversupply but boosted by swings in the strength of U.S. dollar ahead of the expected end of years of zero interest rate policy in the United States later this year.

"In the past 15 years, the global economy was defined by rising commodity prices, zero interest rate policy, and a weak USD. This cycle has now gone into reverse with a decelerating industrial economy in China and the rise of U.S. shale," Bank of America Merrill Lynch said in a report.

"A combination of a strong USD, higher interest rates and subdued growth may keep commodity prices in check in 2015," it added.

China's February crude oil imports from Iran fell 3.7 percent from a year ago to 2.04 million tonnes. China boosted overall imports late last year, taking advantage of cheap oil to build its reserves, but storage tanks could be reaching their limits, forcing a slowdown in orders.