“More recently, Kremlin-linked businessmen Timchenko, Kovalchuk and the Rotenbergs have been offering U.S. counterparts gas concessions in the Sea of Okhotsk, as well as potentially four other locations, according to a European security official and a person familiar with the talks. Russia has also mentioned rare-earth mining opportunities near the massive nickel mines of Norilsk and in as many as six other Siberian locations that are still unexploited, these people said.