CARACAS, Venezuela — Venezuela announced late Friday that it was stopping the latest round of off-again-on-again efforts to improve relations with the United States in reaction to comments by the Obama administration’s nominee for United Nations ambassador.

The nominee, Samantha Power, speaking before a Senate committee on Wednesday, said part of her role as ambassador would be to challenge a “crackdown on civil society” in several countries, including Venezuela. President Nicolás Maduro had already lashed out on Thursday at Ms. Power for her remarks, and late on Friday the Foreign Ministry said it was terminating efforts to improve relations with the United States.

Those efforts had inched forward just last month after Secretary of State John Kerry publicly shook hands with the Venezuelan foreign minister, Elías Jaua, during an international meeting in Guatemala — one of the highest-level meetings between officials of the two countries in years.

Venezuela “will never accept interference of any kind in its internal affairs,” the Foreign Ministry said in a statement, adding that it “considered terminated the process begun in the conversations in Guatemala that had as their goal the regularization of our diplomatic relations.”