Russia and Norway have finally sealed an agreement dividing a long-disputed area in the Barents Sea after decades of negotiations.

Russian Foreign Minister Sergey Lavrov and his Norwegian counterpart Jonas Gahr Stoere ratified the deal during a ceremony in Oslo on Tuesday.

The deal, which splits a 68,000-square mile (175,000-square kilometer) area into two equally sized pieces, has been approved by both countries' parliaments and will come into effect on July 7.

Russia and Norway could not agree on a border during the Cold War period, and negotiations following the 1991 collapse of the Soviet Union also failed.

The agreement opens up a promising oil and gas region in the Arctic, which has become more accessible through global warming.