Russian President Vladimir Putin and Chinese President Xi Jinping Sasha Mordovets | Getty Images

As the annual Shanghai Cooperation Organization (SCO) summit kicks off in the central Chinese city of Zhengzhou on Tuesday, all eyes will be on the group's leading powers—China and Russia—as they seek to consolidate control over Central Asia.

Launched in 2001, the SCO is composed of China, Russia, former Soviet republics Tajikistan, Uzbekistan, Kazakhstan and Kyrgyzstan with the aim of strengthening political, trade, intelligence, security and military ties between the border-sharing members. Iran, Afghanistan, Mongolia, India and Pakistan are currently observers, but the latter two are expected to be official members by next year. China's One Belt One Road (OBOR) project, which aims to recreate the ancient Silk Road trade and infrastructure networks across central, west and south Asia, is expected to feature prominently on the SCO's agenda and experts will be watching how Russian Prime Minister Dmitry Medvedev reacts. "Central Asia is the place where Russian and Chinese interests really merge. As we look into the future, there is potential for political problems in the region and that may create a space for the Russians and Chinese to increase their cooperation," said Rodger Baker, vice president of Asia-Pacific Analysis at Stratfor.

Moscow has traditionally been skeptical of Beijing's expanding influence in an area that it considers its own backyard. Home to some of the world's largest natural gas and coal reserves, Central Asia has experienced geopolitical strife ever since the 'Great Game,' a reference to Britain and Russia's political rivalry during the 19th century.

But while Moscow and Beijing no longer seem to be competing in the resource-rich region, Sino-Russo ties remain shaky and that could affect the SCO's objectives.

Earlier this year, Russian President Vladimir Putin said he was ready to link plans of the Moscow-backed Eurasian Economic Union with the OBOR initiative. Moreover, Russian news agency TASS quoted Medvedev on Monday as saying the SCO will also working alongside OBOR. "But underneath, the two still have a very difficult time trusting each other," stated Baker.

Whereas Russia is more concentrated on international security issues, China has focused its attention on economic governance and multilateral bodies such as the Asian Infrastructure Investment Bank (AIIB), noted Tim Summers, senior consulting fellow at the Asia Program at Chatham House.

"Russia has tried to take its connection with China into a more political and military direction, but China has strongly resisted that and tried to keep the relationship as purely economic. You really see that play out at the SCO meetings," echoed Baker. Ultimately, the relationship between the two heavyweights can be described as somewhere in between an axis of convenience and a deep strategic alliance, said Summers. Since becoming increasingly isolated amid stiff political tensions with the West and Middle East, Moscow has made a pivot to Beijing as sinking oil prices, a crumbling ruble and extended sanctions damages its crisis-hit economy. In turn, China is interested in accessing Russian energy and military research.