Russia is becoming a key oil supplier for the United States, the Wall Street Journal said Tuesday.

"Imports have gone from zero to an estimated 100,000 barrels a day in a matter of months since a pipeline bringing crude from deep inside Eastern Siberia came online," the newspaper wrote.

The paper said the increase in oil supplies is thanks to the Eastern Siberia - Pacific Ocean (ESPO) pipeline system, which is designed to export Russian crude to the Asia-Pacific markets.

Amrita Sen, a commodities analyst for British investment bank Barclays Capital in London, said the United States is diversifying its oil sources because OPEC members, who "historically have been key suppliers to the U.S., are sending more of their oil to Asia."

She said production from other U.S. suppliers, like Mexico, is declining at "hefty" rates, and added that "Russian crude will be important."

MOSCOW, July 7 (RIA Novosti)