The US government has imposed a sweeping ban prohibiting American diplomats, their families and security-cleared contractors in China from engaging in romantic or sexual relationships with Chinese citizens, Associated Press has reported.

The policy applies to staff at the US embassy in Beijing and consulates in Guangzhou, Shanghai, Shenyang and Wuhan, as well as the consulate in Hong Kong. US personnel stationed outside China or those already in pre-existing relationships with Chinese citizens might be exempt, the report said, citing unnamed sources with knowledge of the matter.

A less restrictive version of the policy was introduced last summer, prohibiting US personnel from having “romantic and sexual relations” with Chinese citizens working as guards and other support staff at the US embassy and five consulates in China.

The ban, implemented days before US ambassador Nicholas Burns left his post in January.

Chinese foreign ministry spokesman Guo Jiakun declined to comment on the issue on Thursday afternoon, referring reporters to the US government.