US Secretary of State Antony Blinken said he spoke on Sunday with incoming Chinese Foreign Minister Qin Gang, appointed last week to the post following his role as ambassador to the United States.  On Twitter, Blinken said he discussed the US-China relationship and efforts to maintain open lines of communication in a telephone call with Qin.  On Friday China appointed Qin, its ambassador to the United States and a trusted aide of President Xi Jinping, to be its new foreign minister, as Beijing and Washington seek to stabilize rocky relations.  China's foreign ministry acknowledged that the two spoke by phone.  In a statement on its official website on Monday, the ministry said Qin bid farewell to Blinken during the call, while added that he looked forward to maintaining close working ties with Blinken and promoting Sino-US relations.  Qin, 56, replaces Wang Yi, who had been foreign minister for the past decade. Wang, 69, was promoted to the politburo of the Chinese Communist Party in October and is expected to play a bigger role in foreign policy.  Though Qin sounded optimistic about US-China relations during his brief 17-month stint as ambassador, a post his predecessor occupied for eight years, his tenure nonetheless coincided with deteriorating ties between the two.  Wang's stint as foreign minister saw a sharp rise in tensions between Beijing and Washington on a range of issues from trade to Taiwan.