By David Brunnstrom and Michael Martina WASHINGTON, July 15 (Reuters) - U.S. Deputy Secretary of State Wendy Sherman will visit Japan, South Korea and Mongolia next week, the State Department said, making no mention of any stop in China that had been anticipated in foreign policy circles and reported in some media. After the State Department announcement on Thursday, sources told Reuters that Washington was preparing to impose sanctions on Friday on Chinese officials over Beijing's crackdown on democracy in Hong Kong and to issue a warning to international businesses operating there about worsening conditions. President Joe Biden said the situation in Hong Kong was "deteriorating" when asked about plans for the advisory at a news conference with visiting German Chancellor Angela Merkel.