US Senator Steve Daines is expected to return to China for another round of talks ahead of President Xi Jinping’s planned September visit to Washington, according to people familiar with the preparations.The trip was intended to help finalise the agenda for what both sides hoped would be a high-stakes summit between Xi and US President Donald Trump, one of the sources said.Daines, a Montana Republican, has emerged as an important backchannel figure between Washington and Beijing. He visited...