UNITED NATIONS — The American ambassador to the United Nations, Zalmay Khalilzad, released a statement yesterday that seemed designed to ease tensions between Washington and the U.N.’s development arm. The statement, which was sent to The New York Sun, stood in sharp contrast to a much tougher letter written earlier by one of Mr. Khalilzad’s top aides, Mark Wallace.

Mr. Wallace described an assertion by the U.N. Development Program — regarding a scandal involving its North Korea operation — as “devastating to the U.N. reform effort.” Mr. Khalilzad’s statement, however, supported a compromise that might get the UNDP off the hook.

The UNDP asserted that its actions could not be examined by the top U.N. officer dealing with ethical issues. Instead, the agency promised to conduct its own “external” ethics investigation. The bureaucratic UNDP maneuvering to avoid adverse findings was detailed in Mr. Wallace’s tough letter, made public by several press outlets yesterday.

Mr. Khalilzad accepted a UNDP-proposed approach that was also adopted, at least for the time being, by Secretary-General Ban. “We believe the Ethics Office should have jurisdiction over all U.N. employees, no matter where they work,” Mr. Khalilzad’s statement said. But “in the meantime, we support the idea of an independent outside investigation” into the UNDP’s North Korea operation.

The mixed signals indicated a split within the American U.N. mission about how to deal with several internal issues, such as the UNDP and broader diplomacy, several sources said. Mr. Wallace was hired to deal with U.N. reform issues by Mr. Khalilzad’s predecessor, John Bolton, who had concentrated on fixing the archaic U. N. system. Mr. Khalilzad is much more interested in using the United Nations in world affairs.

The internal gap may not be that wide. “They are playing good-cop bad-cop,” said a former official familiar with the inner workings of the American mission to the United Nations, who spoke on condition of anonymity. Another source said, however, that there are “serious” internal disputes inside the mission.

Last week, the U.N.’s ethics officer, Robert Benson, wrote in a letter to UNDP administrator Kemal Dervis that after several months of examination, he found “prima facie” evidence that a former UNDP employee, Tony Shkurtaj, suffered from retaliation after disclosing details about how rules were violated in the agency’s North Korea office. The UNDP, however, told Mr. Benson that his office had no jurisdiction in the case.

The United Nations should “insist” that the UNDP cooperate with the ethics office,” Mr. Wallace wrote in his August 21 letter. Mr. Ban, however, was “satisfied” with a proposal offered by the UNDP to name an outside official to examine the North Korea affair, according to a U.N. spokeswoman, Michele Montas.

The task of determining whether Mr. Shkurtaj should be protected as a whistleblower, according to the proposal, would be assigned to a yet-to-be-named external official. This even as the U.N. maintains that last year’s creation of an ethics office designed to make such determinations was a great step toward bringing about reform in the organization.

Mr. Shkurtaj wrote a letter to Mr. Ban yesterday, meanwhile, requesting that — rather than making deals meant to be political compromises — the whole matter should be referred to the U.N.’s internal administrative tribunal, “so I may avail myself of further legal recourse.”