HONG KONG—The United States sanctioned an additional 24 Chinese and Hong Kong officials over Beijing’s ongoing crackdown on political freedoms in the semi-autonomous city, just ahead of the Biden administration’s first face-to-face talks with China. The step reflects Washington’s “deep concern” about the erosion of Hong Kong’s autonomy following changes to its election system endorsed by China’s ceremonial legislature last week, Secretary of State Antony Blinken said in a statement Wednesday. Foreign financial institutions that deal with the 24 officials would be subject to U.S. sanctions, the State Department said. The planned changes to Hong Kong’s electoral law give a pro-Beijing committee power to appoint more of Hong Kong’s lawmakers. The move will reduce the proportion of those directly elected and ensures that only those determined to be truly loyal to Beijing are allowed to run for office—effectively shutting opposition figures out of the political process. The U.S. announcement was …