Oil registered heavy losses Tuesday, building on Monday's decline, as myriad factors weighed on sentiment, including talks between Russia and Ukraine, a potential slowdown in Chinese demand and unwinding of trades ahead of the Federal Reserve's expected rate hike on Wednesday.

Both West Texas Intermediate crude, the U.S. oil benchmark, and global benchmark Brent crude settled below $100 per barrel Tuesday, a far cry from the more than $130 they fetched just over a week ago.