Speaking fluent Chinese, Richard Bush believes the two countries should expand areas of cooperation. "Because you expand the areas of cooperation, you build mutual trust and you can have mutual confidence in each other," he said.

"If you always fight about difficult issues, you'll never have a firm foundation," he said.

Bush pointed out that the two countries have done quite a good job in cooperating on North Korea, Iran and climate change. Now director of Center for East Asia Policy Studies at the Brookings, Bush focuses not only on the Chinese mainland and Taiwan, but also Korea and Japan, including China-Japan ties.

In 1995, Bush worked as a national intelligence officer for East Asia and a member at the National Intelligence Council (NIC), shouldering a senior responsibility for analytical work from Japan to Burma.

In 1997, he became chairman of the board of the American Institute in Taiwan (AIT), a non-profit corporation established in 1979 to serve US interests in Taiwan in an unofficial manner. Bush said a lot of people were confused by his job at AIT, since he was based in Washington rather than Taipei.