TOKYO (AP) — Japanese Prime Minister Shinzo Abe says the main cause of escalating tensions between Japan and South Korea is a loss of trust over court rulings ordering Japanese companies to compensate South Koreans for forced labor during World War II.

Japan has imposed export controls on key materials for South Korea’s semiconductor industry and moved to downgrade the country’s trade status. It has insisted that the measures were related to national security concerns and were not in retaliation for the court rulings.

Japan ruled the Korean Peninsula as a colony until the end of the war, and insists that all compensation issues were settled under a 1965 agreement normalizing ties.

Abe, responding to a question Tuesday about the escalating tensions, urged Seoul to take appropriate actions to stop the court procedures.