China’s foreign ministry has declined to comment on President Lee Jae Myung’s upcoming visit to Japan, saying only that exchanges between countries should contribute to peace.

Ministry spokesperson Mao Ning made the remarks at a regular press briefing Friday when asked about the South Korean president’s visit to Japan, set to begin six days after his return from China.

The spokesperson said it was a matter between Seoul and Tokyo and therefore not something Beijing would comment on.

Mao added, however, that exchanges between countries should help promote and safeguard regional peace and stability.

The remarks came amid strained China-Japan relations ever since November, when comments from Japanese Prime Minister Sanae Takaichi suggested the possibility of intervention in a Taiwan contingency, to which China responded earlier this week by tightening export controls on dual-use goods bound for Japan.

President Lee, who paid a state visit to China earlier this week, is scheduled to travel to Nara Prefecture on Tuesday and Wednesday next week for talks with Prime Minister Takaichi.