Sino-US relations have been on a roller-coaster in recent years and that has shaped the direction of bilateral ties although the relationship has managed to scrape past last year's political transition in Washington.

The road to smooth ties, however, got a lot bumpier this year after the arms sale move to Taiwan and US President Barack Obama's meeting with the Dalai Lama.

Yet now, the dark clouds seem to have lifted due to subsequent efforts by both sides.

The Sino-US relationship is one of the most complicated in the world - increased cooperation often follows contentious issues and vice versa.

Both have much in common though, and work side-by-side on a wide range of international and regional matters despite not seeing eye-to-eye on a variety of issues, such as Taiwan and human rights.

On the Taiwan question, an issue central to China's concerns, the two powers share the view that there should be stability across the Straits.

However, Beijing and Washington have long been at odds over US' weapons sales to the island.

Similarly, their inter-dependence in the economic and trade spheres has not obliterated differences on such issues as the exchange rate of the yuan.

Iran's nuclear program and efforts to safeguard the international non-proliferation regime are other areas of divergence.

The two have also yet to resolve challenges stemming from the chiefly ideological confrontation between a decades-old hegemony and an emerging power.

Sino-US ties, on the other hand, cover a wide range of regional and global issues. In recent years, almost all the issues of global significance have been top concerns of both China and the US, a tendency that some scholars have labeled the "globalization of bilateral ties".

In a joint declaration issued during Obama's visit to Beijing in November, the two countries reaffirmed their shared concerns and mapped out bilateral cooperation in areas ranging from security, economic cooperation and climate change.

As a key document issued in the context of globalization, the declaration was an indication of the ever-expanding foundation of Sino-US cooperation under the bilateral context.

It also indicated deepening awareness that global issues were playing a growing role in bilateral ties and that closer cooperation will help the international community deal with looming challenges.

In the declaration, both countries reiterated their respect for each other's sovereignty, territorial integrity and core interests and promised to deal with disputes in the spirit of equality and mutual respect, highlighting that both sides were willing to build an equal and balanced relationship.