The US’ engagement with China and its desire to have a constructive relationship with the Communist nation despite the differences is useful in protecting and advancing the American national interest, the White house has said. “US engagement with China is useful in protecting and even advancing the interest of the US. It doesn’t mean we’re going to always agree, but it does mean it’s worth preserving a constructive working relationship,” White House Press Secretary Josh Earnest said yesterday, ahead of the Chinese President Xi Jinping’s first state visit to the US next month.