Zhang Yesui, China's new ambassador to the United States, had arrived in Washington to take up the post, the Foreign Ministry announced yesterday. The ministry said on its website that Zhang and his wife, Chen Naiqing, also a veteran diplomat, were received by representatives from the Department of State and the Chinese embassy staff at Union Station on Sunday. The announcement confirmed the South China Morning Post's February 5 story of his appointment. It comes at a time when uncertainty lingers over the two powers' relations. China is infuriated by US arms sales to Taiwan earlier this year and President Barack Obama's meeting with the Dalai Lama. The US has been pressing China to revalue the yuan and to lend more support on the climate change issue and impose a new round of sanctions on Iran for its nuclear programme. Formerly China's ambassador to the United Nations in New York, Zhang is China's ninth ambassador to the US since diplomatic ties began in 1979. Foreign Minister Yang Jiechiand two of his predecessors had been promoted to the post from the ambassadorship to the US. Zhang's position at the UN has been filled by Li Baodong, who was the ambassador to the UN office in Geneva.