The United States renewed a travel advisory for China on Thursday that warned American citizens could face arbitrary detention there, a move that came amid tense relations between the countries dominated by trade disputes and the recent American-requested arrest of a high-profile Chinese executive in Canada.

The rights of foreign citizens in China have received renewed focus because of public concern over the fate of an American family barred from leaving the country, Sandra Han and her two adult children, Victor and Cynthia Liu. The arrest in Vancouver last month of Meng Wanzhou, an executive of the Chinese tech giant Huawei, has also raised the specter of potential retaliatory arrests of Americans or Canadians in China.

The travel advisory issued by the State Department on Thursday was a routine renewal of a similar warning issued in January 2018. It urged Americans to “exercise increased caution in China” because of so-called exit bans, a legal tool the authorities there use to bar a person from leaving the country.

People subjected to a ban typically learn of its existence only when they try to leave China, and no method exists for them to determine when the ban has been lifted, the State Department said.