West Texas Intermediate futures for March delivery declined to $31.10 (-1.64%), while Brent crude fell to $33.65 (-1.72%) as market participants continued assessing recent weak data on manufacturing in the world's second-biggest oil consumer China.
The Russian Energy Ministry said on Monday that Russia and Venezuela discussed a possibility of co-operation with OPEC members, however analysts say that it is extremely unlikely that OPEC will co-operate with others to reduce output.
A poll by Reuters showed that U.S. crude oil inventories likely rose by 4.7 million barrels last week. The official data from the Energy Information Administration will be released on Wednesday.