Russia has launched an expedition to the North Pole aimed at proving that a ridge of arctic seabed thought to contain vast oil and natural gas reserves is an extension of continental Russia.

Russian media say two ships, a research vessel and a nuclear-powered icebreaker, left the northern port of Murmansk Tuesday on a five-day journey to the North Pole.

On arrival Sunday, two Russian lawmakers, Artur Chilingarov and Vladimir Gurzdev, and a researcher will board a submersible and descend 4,200 meters to the arctic floor. There, they will plant a Russian flag and a time capsule. Russia made a submission in 2001 to a United Nations' commission claiming the additional territorial waters off of its northern coast. But the United States has opposed the claim, saying those waters should be open to international shipping.

The Commission on the Limits of the Continental Shelf has not yet ruled on the 2001 Russian claim.

Some information for this report was provided by AFP.