"We are ready to join OPEC as observers," Sechin addressed the International Petroleum Week 2015 conference in London.
"We respect this organization, it would like to see us among its members. However, we cannot join OPEC on account of specifics in Russian oil production," the CEO added.
Sanctions against Russia are aimed at undermining the long-term market supply of oil and carries risks for European refinement, Igor Sechin added.
"Sanctions against Russia, for example, are aimed at undermining the long-term supply in the oil market and cause the widening Brent-WTI differential to the detriment of European refinement," Sechin said at an the International Petroleum Week conference in London.
Since June 2014, global oil prices have dropped by about 50 percent due to oversupply in the market. The Organization of Petroleum Exporting Countries' (OPEC) decision in November 2014 not to cut oil output levels contributed to a further slump in prices.
Earlier this week, Citigroup said that the price of a barrel of WTI oil might fall to as low as $20 per barrel "for a while" in 2015.
On Monday, OPEC made a projection, according to which Russia's liquid hydrocarbon production will decline to 10.5 million barrels per day in 2015, compared to 10.57 million barrels in 2014.