WASHINGTON (Reuters) - President Donald Trump’s nominee to be the U.S. ambassador to China said on Tuesday that China can do more to push North Korea to curb its nuclear program, although he did not initially offer any specifics. “I think there’s other things they can do diplomatically and economically to send a clear signal that they, as well as the United States and other countries in the world, do not tolerate this expansion of nuclear technology and missiles,” Iowa’s Republican governor, Terry Branstad, said at his U.S. Senate confirmation hearing. 