Russian President Vladimir Putin reacts during annual news conference in Moscow, Russia December 20, 2018.

MOSCOW (Reuters) - President Vladimir Putin said on Thursday that the United States’ military presence in Japan was complicating the search for a formal peace treaty between Moscow and Tokyo.

Russia and Japan have been in dispute for seven decades over island territories captured by Soviet troops in the last days of World War Two. As a result, they have still not formally ended hostilities.

Putin told reporters at his annual news conference that Moscow was concerned by the deployment of a U.S. air defense system in Japan.