China is still unsure whether North Korean leader Kim Jong-un will visit Moscow next month for a World War II anniversary, South Korea's Ambassador to China, Kim Jang-soo, said Monday.



Russia has said that Kim was among the world leaders who have accepted invitations to join the May 9 ceremony marking the 70th anniversary of the Soviet victory over Nazi Germany in World War II.



North Korea has not officially commented on a possible visit by Kim to Moscow, but it would be his first overseas trip since taking the helm of the reclusive state three years ago.



"Russia seems to be almost confident, but China said that it remains to be seen," the ambassador said when asked about a possible visit by Kim to Moscow.



Ambassador Kim was speaking to South Korean correspondents in Beijing.



Chinese government officials and scholars said it was not possible to predict whether Kim's visit to Moscow would take place because of the North's unpredictable behavior, according to embassy officials who spoke with them.



On Sunday, South Korea's foreign ministry said Seoul will send a special envoy to the May ceremony in Moscow, meaning that President Park Geun-hye will not attend the event.



North Korea is China's only formal treaty ally, but Beijing's leadership has appeared to become increasingly frustrated by the North's nuclear and missile ambitions.



Diplomatic tension between South Korea and China has grown in recent months over the possible deployment of an advanced U.S. missile-defense system in South Korea.



Last week, the Global Times, a state-run newspaper published by China's ruling Communist Party, warned that bilateral ties between Seoul and Beijing would be "shattered" if the Terminal High-Altitude Area Defense (THAAD) system is deployed in South Korea.



U.S. Defense Secretary Ashton Carter said Washington is not yet ready to discuss with South Korea about the possible deployment of the THAAD battery.



Citing the remarks by Carter, Kim sidestepped questions about the matter, saying "It's not at a stage where I can say something because the U.S. has not provided any information." (Yonhap)