Hong Kong leader Carrie Lam has said she keeps “piles of cash” at home because she has no bank account after the United States imposed sanctions on her.
The sanctions were used to target those undermining Hong Kong's autonomy, said Treasury Secretary Steven Mnuchin.
"The United States stands with the people of Hong Kong," Mr Mnuchin added.
The move comes weeks after China imposed a controversial national security law on Hong Kong, which critics say threatens its freedoms.
Lam was targeted, along with 14 other senior city officials, in the toughest US action on Hong Kong yet since Beijing imposed the new law on the territory in late June.
Among those sanctioned are Hong Kong's police commissioner and several political secretaries.
Lam said she was keen to avoid deterring anyone from serving in public office, adding: “To be so unjustifiably sanctioned by the US government, it’s an honour.”
Lam earns HK$5.21m (US$672,000) a year, and is one of the highest paid leaders in the world.
Her remarks sparked a public backlash, with social media users posting photos of coins in their piggy banks at home to contrast with Lam’s wealth.
China has defended its controversial law as necessary to stop foreign interference in Hong Kong and the often violent pro-democracy protests that took place last year.
Earlier this month China issued arrest warrants for six pro-democracy activists, including an American citizen.
Announcing the sanctions on Friday, Mr Pompeo said: "The Chinese Communist Party has made clear that Hong Kong will never again enjoy the high degree of autonomy that Beijing itself promised to the Hong Kong people and the United Kingdom for 50 years.
The latest sanctions were authorised by an executive order Mr Trump signed in July aimed at punished China for its role in Hong Kong's affairs.