Mexico City — Cuba’s foreign minister on Monday delivered a searing rebuke of President Trump’s new policy toward the island nation by calling it a “grotesque spectacle” and vowed that his country “will never negotiate under pressure or under threat.”

The remarks by the foreign minister, Bruno Rodríguez, at a news conference in Vienna, was the Havana government’s first official response to Mr. Trump’s announcement last week that he was scaling President Barack Obama’s initiatives to improve relations with Cuba and would reinstate some travel and commercial restrictions.

“Without doubt, the politics of Mr. Trump mark a step backwards in bilateral relations, and this has been recognized by countless voices inside and outside of the United States, who have roundly rejected the announced changes,” Mr. Rodríguez said.

Mr. Trump said the reversal was meant to apply pressure on Cuba’s Communist government by starving it of much-needed foreign currency. The hope, shared by Cuban-Americans who harbor a deep resentment of the Castro government, is to encourage a more democratic state that upholds human rights and holds free fair elections.