UNITED NATIONS – Deputy Secretary-General Mark Malloch Brown yesterday threw the United Nations further into the thick of America’s partisan politics when a fresh personal attack he had made on the American U.N. ambassador, John Bolton, was published.

Top Bush administration officials, meanwhile, added their voices to that of Mr. Bolton, assuring the U.N. top brass that they fully stand by the ambassador’s outrage at the “unprecedented” attack on a member state.

The new salvo in the U.N.’s exchange of hostilities with Washington heightened tensions that Mr.Malloch Brown escalated earlier this week by denigrating America’s “heartland” to Democratic policy wonks, using partisan buzzwords like “Fox News” and “Rush Limbaugh.”

Washington politicians and Turtle Bay insiders say outgoing members of the U.N. administration, led by Secretary-General Annan, are using their final months in office to exact revenge against American conservatives.

It is not only that Mr. Malloch Brown plays partisan politics in Washington, in violation of one of the most fundamental U.N. rules forbidding officials from becoming involved in international national politics, said Senator Coleman, a Republican of Minnesota, “He is playing bad American politics,” Mr. Coleman told The New York Sun.

Countering assertions by U.N. and former Clinton administration officials, one Senate foreign policy staffer, who said he was not authorized to be quoted by name, said Mr. Malloch Brown’s words “will do nothing to better the relationship between the U.N. and Washington.” Instead, he added, they “only lead one to wonder what office the deputy secretary-general thinks he’s running for.”

The Pakistani ambassador to the United Nations, Munir Akram, noted yesterday that Mr. Malloch Brown had “also attacked the group of 77,” which represents poorer countries that oppose deep changes pushed by Mr. Annan. But Mr. Akram acknowledged that as one of the leaders of the group, no U.N. official had ever attacked his country specifically, or him personally.

Yesterday, Mr. Malloch Brown aimed his attack directly at Mr. Bolton, who had to go through a bruising Senate confirmation last winter. Mr. Bolton’s recess appointment will run out by the end of the year, when the partisan fight over his appointment might reignite. Quotes in a USA Today article profiling Mr. Bolton yesterday seemed designed to add ammunition to American senators who might oppose reappointing him.

“He’s a real force here, but in a way that provokes a lot of reaction and opposition from others,” Mr. Malloch Brown was quoted as saying of Mr. Bolton. In the aftermath of the U.N. debate on Iraq, he added, “what you needed was an ambassador who would heal, not deepen, rifts.”

Mr. Annan yesterday told reporters that while there may have been “one or two things” in Mr. Malloch Brown’s Tuesday speech that he had disagreed with, he supported the message. It was time to “put it behind us and move on,” he added.

In London yesterday, however, Mr. Bolton said it was “illegitimate for an international civil servant to criticize what he thinks are the inadequacies of the citizens of a member government.” One response that “I fear substantially,” he added, was that “this will throw our efforts in the United Nations reform process into disarray.”

Backing him, Secretary of State Rice called Mr. Annan on Wednesday, and yesterday Undersecretary of State Nicholas Burns also called Mr. Malloch Brown.

Their message was “that we were very disappointed by the fact that a high-ranking U.N. official would single out a member country,” a State Department spokesman, Sean McCormack, said. “We find this very disappointing, almost unprecedented. I don’t think that we could really find another example of that before.”

A top aide to Mr. Annan, who asked not to be identified, noted that Mr. Malloch Brown’s interview with USA Today, where he attacked Mr. Bolton personally, took place last month, and was not related to Tuesday’s speech.

“The message from the United Nations to the U.S. is a positive one,” Mr. Annan’s spokesman, Stephane Dujarric, told the Sun yesterday. “It’s one calling for strong and sustained engagement from the U.S. in the organization.”