Tillerson to press China on North Korea in tough first Asia trip

By David Brunnstrom and Yeganeh TorbatiWASHINGTON (Reuters) - U.S. Secretary of State Rex Tillerson faces a tough first trip to Asia this week when the former oil executive will seek to reassure nervous allies facing North Korea's growing nuclear and missile threat and press China to do more on perhaps the most serious security challenge confronting President Donald Trump.Tillerson will visit Japan and South Korea before heading to Beijing, where he is expected to firm up a U.S. visit by Chinese