Japanese Prime Minister Shinzo Abe and South Korean Prime Minister Lee Nak-yon agreed on Thursday on the need to cooperate on North Korea despite tense bilateral ties, but Abe reiterated that Seoul needed to keep its promises for relations to improve, Aljazeera reports.

Ties between the two countries have deteriorated since South Korea's top court last October ordered some Japanese firms to compensate Koreans forced to work in their wartime mines and factories.

Japan, which says the matter was settled by a 1965 treaty, calls the decision a violation of international law, and the feud has spilled over into trade and security matters.

About 100 journalists were present at the start of the talks in Tokyo, the highest-level meeting between the two sides since the row began. The meeting began with a handshake.

Abe urged South Korea to keep its promises - a reference to the 1965 treaty - in order to restore relations, according to a statement issued by Japan's foreign ministry.

"Our two nations are important neighbours for each other, and keeping in contact over North Korea, bilateral relations and our ties with the United States are quite important," Abe was quoted as telling Lee.

"Relations are currently in quite a severe state but should not be left that way. If South Korea can keep bilateral promises, that could be a chance to return to a healthy relationship," Abe added.

The statement also quoted Lee as saying he shared the view that dialogue was important, while a parallel statement from South Korea's foreign ministry said Lee agreed relations should not be left in their current difficult state.