Asked if the Moon administration sees the North's freeze on its nuclear program as a condition for denuclearization negotiations, Chung said that the freeze could be an "entrance" to the negotiations.
South Korea and the United States agreed to deploy the Terminal High-Altitude Area Defence (Thaad) anti-missile system in response to the growing missile threat from North Korea.
Chinese Foreign Ministry spokeswoman Hua Chunying said the exchanging of congratulatory messages was consistent with usual practice. Since the establishment of formal diplomatic relations in 1992, both countries have jointly been celebrating the anniversary every five years.
Chen Zhu, vice-chairman of the National People's Congress (NPC) Standing Committee, said at a celebration of the anniversary in Beijing on Wednesday that China is willing to work with the ROK to stay true to their original aspirations, reinforce mutual trust, properly handle disagreements and push the ties back on the track of steady and healthy development.
Qatar restores diplomatic ties to Iran amid regional crisis
The statement did not mention any more details including the ambassador's name or the exact time of his return to Tehran. It is essential for Saudi Arabia to change its views on regional issues, the Iranian foreign minister said.
With concerted efforts by China and South Korea, Xi pointed out, bilateral relations had been developing since the establishment of diplomatic ties 25 years ago, bringing tangible benefits to the two peoples and making positive contributions to regional peace and development.
Moon said the development is the result of the governments and peoples of the two countries regarding their efforts to enhance mutual understanding and trust.
Kang later Thursday departed for Moscow, where she is scheduled for talks with Russian counterpart Sergey Lavrov ahead of Moon's visit to Russia to attend the Eastern Economic Forum in Vladivostok early next month. Instead, China sent its science and technology minister to a South Korean embassy event in Beijing. Wan also serves as vice chairman of the Chinese People's Political Consultative Conference, the country's top political advisory body, which is a vice premier-level position.
It was the Chinese side that initiated to hold events separately this year.