Hong Kong’s securities regulator has privately advised financial institutions they can implement US sanctions without automatically violating a tough national security law imposed on the city by Beijing.

The move, which is aimed at reassuring foreign investors in the Asian financial hub, comes as international companies complain that the government has yet to release concrete guidelines on the law’s implementation months after its introduction.

Beijing imposed the national security law on Hong Kong in June following more than a year of anti-government protests. In response, the US announced sanctions requiring financial groups to cut ties with Hong Kong and Chinese officials involved in the legislation, including Carrie Lam, the city’s leader.