Chinese President Xi Jinping (R) shakes hands with US Vice President Joe Biden (L) inside the Great Hall of the People in Beijing on December 4, 2013. Biden arrived in Beijing to raise concerns over a Chinese air zone ramping up regional tensions, looking to bolster ties while also underscoring alliances with Tokyo and Seoul. His trip follows weeks of furore after Beijing declared an "air defence identification zone" (ADIZ) covering East China Sea islands disputed with Japan. AFP PHOTO / POOL (Photo by LINTAO ZHANG / POOL / AFP)