Japan and Mongolia signed a free trade agreement expected to open the landlocked frontier market to more Japanese auto exports and strengthen Tokyo's leverage with a key partner in its dealings with North Korea.

Prime Minister Shinzo Abe and his Mongolian counterpart Chimed Saikhanbileg signed the agreement Tuesday at a summit where Japan also was due to offer Mongolia concessional loans for building a new airport in Ulan Bator, the capital.

Free trade talks began in 2012 and the two countries reached a basic accord last July.

Mongolia's imports from Japan, mostly vehicles, are roughly 16 times the size of its exports to Japan.

Mongolia has served as a conduit for Japan's talks with the North Koreans on abductions of Japanese decades ago.