Official Chinese media reports about a U.S. diplomat who met with student leaders of Hong Kong's pro-democracy movement "have gone from irresponsible to dangerous" and must stop, U.S. State Department spokeswoman Morgan Ortagus said on Friday.

"Chinese authorities know full well, our accredited consular personnel are just doing their jobs, just like diplomats from every other country," Ortagus added in a tweet.

She did not elaborate on the nature of the reports, but said: "This must stop."