Word that OPEC kingpin Saudi Arabia would defend its economic interests sent an already battered oil market into a tailspin during the Tuesday session.

Crude oil prices suffered major losses Monday, with the price for the U.S. benchmark, West Texas Intermediate, and Brent, the global benchmark, reaching five-year lows.

Oil prices are about 50 percent lower than they were in June 2014. Prices have declined dramatically since late November when members of the Organization of Petroleum Exporting Countries opted to keep production steady despite tough market conditions.

Saudi King Abdullah in a speech read by Crown Prince Salman bin Abdulaziz suggested the kingdom was staying the course even with oil prices off about 25 percent since the OPEC meeting in November.

"The kingdom will continue to defend its economic interests and its international status through a national perspective that takes into account its citizens' prosperity, sustainable development and the interests of present and future generations," the king's message read.

Brent for February delivery greeted the message by dropping more than 2 percent from the previous session to trade near $52 per barrel. WTI followed suit, shedding about 2.2 percent from Monday's close to sell near $49 per barrel.

For U.S. consumers, the low price of oil is seen as a de facto source of economic stimulus because of lower energy expenses. Globally, however, the steady decline is creating concerns for investors about the health of the overall economy.

U.S. stock market indices suffered major losses Monday as oil prices continued to shed value. Most European indices Tuesday were treading water, though the region's economy is struggling to gain traction.

Japan's Nikkei index was off 3 percent at the end of the trading day Tuesday.