Obama's policy toward China, like his other policies, too, has yielded mixed results. But despite mutual frustration over hacking, and maritime security and human rights issues, the list of Sino-US cooperation is long.

China and the US succeeded in converting their tense relations, as seen at the 2009 Copenhagen climate conference, into a cordial partnership that led to the signing of the Paris Climate Agreement. The meeting between President Xi Jinping and Obama on the sidelines of the G20 Summit was another example of the two countries' fruitful cooperation.

China-US cooperation to promote nuclear nonproliferation is another major success. Beijing and Washington worked together to advance the P5+1 negotiation with Iran to reduce nuclear threat and conclude the Joint Comprehensive Plan of Action in July 2015.

But the Korean Peninsula issue continues to pose a challenge to the regional peace, with the Democratic People's Republic of Korea intensifying its nuclear program and the US' deployment of the Terminal High Altitude Area Defense system in the Republic of Korea has made matters worse. So, in conjunction with China, Obama has to adequately address each of these issues as well as to decouple them. Otherwise, growing distrust will undermine their concerted efforts to bring stability to the peninsula and consolidate the non-proliferation regime.

The South China Sea issue is not a part of the G20 Summit, but still it's important for China and the US to agree to respect each other's sovereign rights and maritime interests. For example, the US should stop taking sides in the South China Sea disputes, and China should respect US interests in international air space and sea. So it will be a welcome change to see Obama employing an approach at what could possibly be his last official meeting with China's top leaders that shows reconciling interests isn't necessarily mission impossible.

The author is a professor at and associate dean of the Institute of International Studies, Fudan University.