The visit by senior Chinese military officials to Russia shows growing military cooperation and relations between the two countries, experts said.
The Chinese delegation headed by Xu Qiliang, vice chairman of the Central Military Commission, flew to Russia on Sunday following an invitation from Russian Defense Minister Sergei Shoigu, according to China's Ministry of Defense.
Xu was joined by Liu Sheng, deputy director of the PLA General Armaments Department, and PLA navy and air force commanders.
"The visit from officials of China's ground, air and naval forces shows the broad military cooperation between China and Russia," Li Shuyin, a Beijing-based expert on Russian studies, told the Global Times.
Xu's visit is a routine activity of a Sino-Russian committee on military cooperation, and the mechanism of such regular exchanges shows that Sino-Russian military cooperation is on a fast track, said Li.
Li added that technology cooperation is the essence of Sino-Russian military cooperation, and that Russia is eager to boost military cooperation as the country faces economic and political challenges, and Moscow also needs military trade to improve its GDP.
There is speculation that Xu's visit may involve a deal on military hardware, following reports that China will purchase SU-35 fighters and S-400 Triumf missile systems from Russia.
"The contract was supposed to have been signed either at the end of 2014 or the start of 2015," Russian military manufacturer Sukhoi First Deputy Director General Boris Bregman told the Global Times at the China International Aviation and Aerospace Exhibition in November 2014.
According to an ITAR-TASS report in April 2014, negotiations between Russia and China to purchase S-400 Triumf missile systems were underway.
If a deal to purchase Su-35 fighter jets and S-400 missiles is reached, the trust between China and Russia will reach a new level, added Li. "They will help strengthen China's military capability and improve China's presence in the South China Sea and East China Sea."