The U.S. State Department said on Monday that the Chinese government had blocked a U.S. Patent and Trademark Office employee visiting the Asian country in a personal capacity from leaving. "We are tracking this case very closely and are engaged with Chinese officials to resolve the situation as quickly as possible,

China has declined to comment on the alleged exit ban, saying only that it handles all cases according to the law.

China has stopped an American citizen who works for the US Commerce Department from leaving the nation for several months, according to media reports — an episode that coincides with Beijing and Washington trying to arrange a leaders’ summit so they can address their differences on trade.