Japanese Prime Minister Shinzo Abe on Monday described South Korea as Japan's "most important neighbour".

His comments signalled a possible thaw in Tokyo's recently tense relations with Seoul.

"I hope (South Korea) will keep its promise between the two countries and build future-oriented bilateral relations," he added.

Animosity between the two countries, linked to Japan's imperial past, have deepened this year, worrying the United States, which wants to bolster a trilateral alliance to better cope with a rising China and North Korean nuclear threats.

Japan tightened its control of major export items to South Korea in apparent retaliation for South Korean court rulings that ordered Japanese companies to compensate wartime Korean employees for forced labour.

In response, South Korea threatened to terminate a bilateral intelligence-sharing deal.