WASHINGTON — The Trump administration rebuked human rights watchdog organizations on Wednesday, blaming them in part for its decision this week to withdraw from the United Nations Human Rights Council.

In a scathing letter, Nikki R. Haley, the American ambassador to the United Nations, criticized the organizations for opposing her failed push last month for a General Assembly vote on changes to the council, the world’s most important human rights body.

“You put yourself on the side of Russia and China, and opposite the United States, on a key human rights issue,” she wrote to 18 organizations that criticized her attempt. “You should know that your efforts to block negotiations and thwart reform were a contributing factor in the U.S. decision to withdraw from the council.”

The United States withdrew from the council on Tuesday to protest its frequent criticism of Israel’s treatment of Palestinians. The United States now joins Iran, North Korea and Eritrea as the only countries that refuse to participate in the council’s meetings and deliberations.

It was the first time a member has voluntarily left the council.

Several recipients of Ms. Haley’s broadside said that her proposed changes could have led to amendments from Russia, China and other nations to weaken the council.

Human Rights Watch was among the nongovernmental organizations that opposed Ms. Haley’s push for a General Assembly vote. “The risk was that it would have opened a Pandora’s box of even worse problems,” Louis Charbonneau, the group’s United Nations director, said in an interview.

“The idea that human rights groups were trying to undermine genuine attempts to reform the council, or that we were working with countries like Russia, is outrageous and ridiculous,” Mr. Charbonneau said.

Western governments largely agreed with the watchdog groups’ view on the issue, derailing the American overhaul effort.

“To this date, we have received not one written edit from a single member state,” Ms. Haley wrote in the letter on Wednesday.

State Department officials said Ms. Haley’s rebuke grew out of intense frustration that the groups banded together to oppose her efforts without talking to her first. She was also frustrated that a year of work and consultations had so far yielded few results, they said.

In a speech on Tuesday, Ms. Haley said she would continue to work to overhaul the council.

But without the United States, changes are far harder to achieve, according to the rights organizations that said the Trump administration has a poor track record for such negotiations.