UNITED NATIONS — Ban Ki-moon was sworn in yesterday as the new U.N. secretary-general and amid widespread accolades for his predecessor’s 10-year tenure, he shifted the mood at the U.N. General Assembly, vowing to launch an “Operation Restore Trust.”

In an indication that Mr. Ban could be friendlier to American interests than his predecessor, the former South Korean foreign minister condemned Iran’s recent conference of Holocaust deniers and its president’s call to wipe Israel off the map, calling both “unacceptable.”

Mr. Ban did not come off as well with French-speaking nations, however, as he struggled almost comically to understand a question posed in French during a press conference. To make matters worse, the questioner, a reporter from the Canadian Broadcasting Corporation, had asked whether French should remain the “second official” working language at the United Nations.

The incoming chief, who is scheduled to take office January 1, has been tight-lipped about the much-anticipated nominations of top officials. Yesterday he told reporters that he is in the process of reviewing every top manager at the United Nations. “In due course,” the first nomination to be announced will be deputy secretary-general, a position now held by Mark Malloch Brown, Mr. Ban said. He added that he is looking at “several names, with a preference for women candidates.”

Until recently, insiders said the top candidate on Mr. Ban’s short list to replace Mr. Malloch Brown was the U.N. population fund chief, Thoraya Ahmed Obaid, a Saudi national educated mostly in America, where she has lived since the 1960s. Alternatives include several other female Arab and African diplomats and a former Colombian ambassador to the United Nations, Maria Angela Holguin.

In addition to the expected new top officials, Mr. Ban has brought with him to the United Nations three trusted aides with whom he worked closely at the Foreign Ministry in Seoul. Among them, the highest-ranking is expected to be Kim Wonsoo. The second is Yoon Yeocheol, while Mr. Ban’s former spokeswoman, Song-ha Choi, is already at the U.N. spokesman’s office, though she is not expected to be named top spokeswoman for the secretary-general.

Mr. Ban, who is known in South Korea as a quiet yet forceful manager, set a new tone for the United Nations yesterday during a morning ceremony in which Secretary-General Annan and his tenure received glowing tributes. Most speakers highlighted the awarding of the 2001 Nobel Peace Prize to the United Nations and its secretary-general as Mr. Annan’s top achievement.

But while the speakers focused on Mr. Annan’s accomplishments, many diplomats saw Mr. Ban’s speech afterward as a dig at U.N. management during the last 10 years, which have been marked by a clear decline in the prestige of the institution.

Although he said his predecessor has “given the United Nations new relevance to the people’s lives,” Mr. Ban showed an understanding of the low esteem in which the world body is held in many countries, including America, saying he hoped to “restore trust in the organization.”

He also made reference to its atmosphere of lax management and oversight, and to the perception that Mr. Annan and his top executives rarely took responsibility for any failure. “I will seek to set the highest ethical standard,” Mr. Ban said. “I assure you that I will lead by example.”

Mr. Ban recently told The New York Sun that he would sign a financial disclosure form and make his finances public, which he said he did for years as South Korean foreign minister. Mr. Annan initially refused such a form and remains opposed to releasing it to the public.

At the press conference yesterday, Mr. Ban said he is planning to launch “Operation Restore Trust.” He added, however, “I hope this mission is not mission impossible.”

He noted that the United Nations has been criticized for its “inability and inefficiencies during the last many years” and that a second trust was lost “among member states and between member states and the Secretariat.” He promised to “try to play a bridge role” to overcome that mistrust.

On global politics, Mr. Ban said the Middle East is “the most serious issue with which we must deal.” At the heart of it, he said, is “the relationship between Israel and the Palestine authorities,” followed by Lebanon and Iraq. He said he would try to “energize” the so-called Quartet of America, the European Union, Russia, and the United Nations.

Asked about Iran yesterday, Mr. Ban said, “Denying historical facts, especially on such an important subject as the Holocaust, is just not acceptable. Nor is it acceptable to call for the elimination of any state or people. I would like to see that fundamental principle respected both in rhetoric and practice by all the members of the international community.”