The response from the Ministry of Foreign Affairs in Beijing promised to continue a pattern of tit-for-tat punishments that have accompanied the sharp downward turn in relations between the two countries on a variety of fronts, from trade to technology to human rights.

China was swift to criticize Mr. Trump’s latest actions, which he announced at a rambling White House news conference on Tuesday. Those moves, along with his remarks, underscored the extent to which relations with Beijing have become intertwined with the American presidential election.

Mr. Trump said he had issued an executive order revoking the special trading status that Hong Kong had enjoyed for more than two decades, following the Chinese government’s imposition of a sweeping new national security law there.

The law came into force on June 30, and its chilling effect on political freedoms in the city — which, under a formula called “one country, two systems,” is supposed to have a high degree of autonomy from China — has already been evident in a series of arrests and police raids.

Mr. Trump also signed legislation, adopted overwhelmingly in May by Congress, that authorizes the administration to impose sanctions on officials or institutions, including banks, that were found to have undermined Hong Kong’s semiautonomous status.

His executive order, besides revoking the territory’s special trading status, calls for sanctions against people deemed to have been involved in a variety of acts in Hong Kong, including arrests made under the new security law and actions that undermine democratic processes or limit the news media’s freedoms.

Officials in Beijing had clearly anticipated the moves, but they reacted harshly nonetheless.

“The act on the United States side maliciously denigrates Hong Kong’s national security legislation, threatens to impose sanctions on China and gravely violates international law and basic rules of international relations,” the Ministry of Foreign Affairs said in a statement posted on Wednesday morning in China, not long after Mr. Trump finished speaking.