The issue of US arms sales to Taiwan always lingers over the relations between Beijing and Washington. Only a year after US President Barack Obama took office, the Pentagon agreed to a 6.4-billion US dollar arms sale to Taiwan.

In response, China suspended some military exchanges with the US, saying it would review co-operation on major issues and imposed sanctions on related companies. And, as the 2012 general election approaches, some US lawmakers have started pressuring the Obama administration to sell F-16 fighter jets to Taiwan, at a cost of 4.5 billion US dollars. US media said Washington will announce its decision in September.

Rong Ying, Vice President of China Institute of Int’l Studies, said, "The issue of the US arms sale to Taiwan has been dominating relations between China and the US and it is a core issue between the two countries. Under the current circumstances, China is waiting for a response from Biden during his visit."