The chief executive of Royal Dutch Shell PLC on Thursday said that whichever political party wins the U.S. presidential election in November should formulate an energy policy with a view to achieving "near energy independence" within 20 years.

Swiss CEO Peter Voser, who heads Europe's largest oil company, was speaking after his company's second quarter earnings showed a greater than expected decline in profits, due mostly to lower oil prices.

At a meeting with analysts in London, Voser said that energy independence could be possible using a combination of newly-available technologies for extracting oil in difficult-to-reach areas, including the icy Alaska seas where Shell is undertaking exploratory drilling this summer, deep sea operations in the Gulf of Mexico, heavy oil sands, and especially developing the US's large natural gas reserves would all help.

"On top of it all, it would bring manufacturing industries back into the country, petrochemical industry back into the country, because you have a cheap feedstock," in the form of natural gas, Voser said.