Russia and China are reportedly working together to develop a new transport helicopter. Above, military helicopters fly in formation during a training session on the outskirts of Beijing, July 2, 2015. Reuters/Jason Lee

Russia and China are working towards jointly developing a transport helicopter, with companies involved expected to sign a contract by the end of the year, Russian news agency RIA Novosti reported, according to Sputnik News. The helicopter would be able to carry as much as 15 metric tons and is expected to be tailored for use in countries with hot climates and mountainous areas.

"The concept is already there," Viktor Kladov, a spokesman for Rostec, a Russian state company, reportedly said. "Now, the design and manufacturing company Russian Helicopters is beginning talks with its Chinese counterparts, related to the technical characteristics of the new helicopter."

The cooperative effort comes as both China and Russia have displayed increasing military aggression in their respective parts of the world. Western countries have accused Russia of supplying weapons and manpower to rebels in eastern Ukraine as part of a conflict in which more than 6,400 people have died since 2014. China, meanwhile, has been flexing its muscle in the South China Sea, launching drilling rigs in the disputed territory as well as building artificial islands that it said would host facilities used for military defense.

Russia's Mil Design Bureau, which designs and manufactures a variety of helicopters, including purportedly 90 percent of those used by Russian military and police forces, is slated to design the new helicopter, while Russian Helicopters is expected to handle production. China could order at least 200 helicopters through 2040, Sputnik News reported. Russian Helicopters and the Aviation Industry Corporation of China had reportedly signed an agreement in May to develop such a helicopter.

The agreement falls into line with steadily deepening Sino-Russian ties that have grown even stronger in recent months. The two countries signed 32 different bilateral agreements in May, the Atlantic reported, and that same month they held a naval drill, "Joint Sea 2015," in the Mediterranean Sea -- long perceived as under the purview of NATO countries. In that exercise, Russian and Chinese guided missile cruisers, frigates and other warships practiced operations "simulating the protection of safe shipping in remote areas of the World Ocean," a spokesman for the Russian Defense Ministry told Interfax, the Diplomat reported.

“Naval forces of both countries made concerted efforts to explore new formats of joint exercises, and learn valuable experience from each other, which has made the drills a success,” Du Jingchen, deputy commander of the Navy of the People’s Liberation Army of China, added.