What can we learn from 2015 about China-US relationship? Three things come to mind. First, dialogue is the best way to address our differences. President Xi Jinping paid a state visit to the United States from Sept 22 to 25, his first such visit after assuming office.

Prior to Xi's visit, I made two trips to the US where I met a lot of American friends with whom I discussed China-US relationship. They all sounded depressed and were genuinely worried about the future prospects. They cited divergences on numerous issues between the two countries, such as cyber security, the South China Sea issue and human rights.

The US media played up these divergences. They presented cyber security as the most contentious issue and asserted that the US was a major victim of hacking "originating from China". China kept denying the allegations, but the atmosphere surrounding China-US ties continued to worsen. Rumors had it that the US government was considering imposing sanctions on China for the "hacking attacks", and people feared Xi's state visit to the US might end up in failure.

Cyber security is a highly controversial and sensitive issue. Yet it just took a few days for China and the US to reach a consensus on the issue. It is an eloquent proof that dialogue is the best way to address differences.

Second, China-US cooperation made a major difference to the UN climate change conference in Paris. Climate change poses a formidable challenge to mankind. No country, no matter how powerful it is, can meet this challenge alone. People across the world have no choice but to unite to meet this challenge, or else the survival of human race could be at stake.

The successful China-US cooperation on climate change is a milestone not only in bilateral relations but also in international relations, and the importance of this success cannot be overstated.

Third, the differences between Beijing and Washington on the South China Sea issue are getting more acute. The US has said it will not take sides on the issue of ownership of the isles and reefs in South China Sea but the freedom of navigation and over-flights in the area should be guaranteed. China, on its part, does not see any problem with regard to the freedom of navigation and over-flights in the South China Sea, because it cares more than any country about such issues.

On Oct 27, 2015, America's guided-missile destroyer USS Lassen sailed to the waters near China's Zhubi Reef and Meiji Reef. Beijing sought dialogue with Washington on the subject by referring to the US-China Memorandum of Understanding on the Rules of Behavior for the Safety of Air and Maritime Encounters, which was signed in November 2014.

Some American scholars called these exchanges between China and the US the "South China Sea Model", and this model has enabled the two sides to hold dialogue to manage their differences.

China and the US, a rising power and the established superpower, are bound to have differences on security issues. What matters is that the two sides have a mechanism at their disposal to deal with the differences. The "South China Sea Model" is one such mechanism.

Looking down the road, we know 2016 will be a complicated year for China-US relationship. The US presidential election campaign is unfolding, and it has always been a big show. The candidates can say anything which they think could boost their campaign. In addition to that, Taiwan will hold elections this month and the US has decided to sell the island weapons worth $1.83 billion.

All these factors may make China-US relationship complicated this year. I hope Beijing and Washington, drawing on the positive experience of 2015, will do their best to navigate their relationship smoothly through the rough waters because their ties are crucial for maintaining international peace and security and they cannot allow it to drift.

The author is a member of the Foreign Policy Advisory Group of the Chinese Foreign Ministry.