NAGOYA, Japan, Nov 22 (Reuters) - Japan's foreign minister agreed on Friday to visit Russia next month for talks about a formal World War Two peace treaty, a ministry official said, following a decades-old dispute that has prevented the countries from reaching a pact.

Toshimitsu Motegi agreed with counterpart Sergei Lavrov to visit Russia in mid-December and discuss the issue, the official said at a briefing on the sidelines of a meeting of the Group of 20 (G20) nations in the central Japanese city of Nagoya.

Japan claims a string of Russian-controlled western Pacific islands. The territorial row has precluded a formal peace treaty between the two countries. (Reporting by Kiyoshi Takenaka; Writing by David Dolan; Editing by Alex Richardson)