The U.S. government has told Chinese conglomerate HNA Group Co. it has to sell its majority stake in a Manhattan skyscraper whose tenants include a police precinct tasked with protecting Trump Tower, according to people familiar with the matter.

The Committee on Foreign Investment in the U.S., which reviews whether foreign investments in the U.S. represent national-security risks, informed the Chinese company a couple of months ago it had to divest itself of its holding in the building, according to these people. CFIUS, as...