The group of Russian sportsmen planned a canoe trip down the Yurungkax River, a remote area in one of the longest mountain chains in Asia, the Kunlun Mountains, but they failed to turn up 12 days later as scheduled.
The Russian Canoe Federation requested the Russian embassy in China help find the missing sportsmen.
The agency said that rescuers have searched a 406 square kilometer (156 square miles) region, as well as an 80 kilometer section (30 square miles) of the Yurungkax River.
The rescue operation has been hindered by the terrain and mountains, which are up to 6,000 meters above sea level (19,700 feet), the agency said.
Russia's Emergency Situations Ministry proposed sending an IL-76 aircraft and a Bo-105 light reconnaissance plane to assist with the operation in China.
The Chinese authorities have given permission for the Russian aircraft to enter China's airspace.
