New Secretary-General Ban Ki-moon on Wednesday announced his picks for two of the top posts at the United Nations this week — and one of those choices is controversial.

Ban, the former foreign minister of South Korea who started his new job Tuesday, named Mexican Alicia BarcenaKofi Annan's former chief of staff — to the key post of administration and management, a job previously held by American Christopher Burnham.

The administration and management job traditionally has gone to an American.

Before the announcement was made, one U.N. official told FOX News the appointment of a non-American to the post would be a "disaster" for the U.S.-led effort to reform the United Nations.

The U.S. mission at the United Nations told FOX News it put forth at least one candidate for consideration.

Britain's ambassador to France, John Holmes, was named undersecretary-general for humanitarian affairs, replacing Norwegian Jan Egeland. Holmes is a career diplomat who served as a private secretary to British Prime Minister Tony Blair and his predecessor, John Major.

'Disaster' for Reform?

The under-secretary-general for administration and management has for years been an American and is traditionally responsible for some of the most important financial matters at the United Nations: The world body's debt, executing personnel cuts to balance budgets and pursuing countries who are behind in paying dues.

The position is also responsible for the U.N. watchdog that ensures the secretariat's integrity — the Office of Internal Oversight Services (OIOS) — and the U.N.'s legal and human resources departments.

Burnham, the last person to hold the post, was previously the chief financial officer in the U.S. State Department and had been state treasurer of Connecticut. He was appointed by former Secretary-General Annan in 1995 and spearheaded the institutional reform efforts that were promised by Annan and resisted by a large number of developing countries. Burnham left in December to take a job in the private sector.

Burnham was preceded by fellow Americans Catherine Bertini, appointed by Annan after she managed the World Food Program, and Joseph Connor. Before Connor, Melissa Wells and former Attorney General Richard Thornburg held the post.

The United States is the largest contributor to the United Nations, with American taxpayers covering nearly a quarter of its budget.

Putting someone other than an American at the office's helm would be perceived in many quarters as a slap at the United States at its push for U.N. reform, which has met much resistance from so-called G-77 group of developing nations, who are allied on the reform issue with China, the U.N. official told FOX News.

"There is talk that that top managerial job will not go to the United States, which raises concerns for the ability of the United States to ensure the kind of oversight that U.S. taxpayers are entitled to expect," Anne Bayefsky of Eye on the U.N. told FOX News before Ban made his announcement Wednesday.

G-77 countries have also argued that more efforts need to be made to install officials from countries other than the five veto-wielding countries: the U.S., China, Russia, France and Great Britain.

"The issue of equitable geographical representation is understandably a concern for developing countries that have a marginal presence in the secretariat," Ambassador Nirupam Sen of India told the G-77 during a March 2006 address, as reported by Inter Press Service.

"While we await what has been termed as the 'proactive' approach to recruitment, any new system that compromises on transparency and which does not address the need to ensure a representative composition of the secretariat will have no possibility of gaining acceptance," he added, also calling on the secretariat to "scrupulously follow" the principle established by the General Assembly that no member state have a monopoly of any post in that office.

Sen pointed to the department of management post, adding that the General Assembly should ensure there is no monopoly on senior posts by nationals of any state or group of states.

Scandalous Ties

Barcena's career has focused not on management expertise but on public policies for sustainable development and the linkages between environment, economy and social issues. According to the United Nations, she focused her work on financing for sustainable development.

Prior to being named chief of staff to Annan, she served as deputy executive secretary of the Economic Commission for Latin America and the Caribbean (ECLAC) where she promoted the implemented the U.N.'s Millennium Development Goals in Latin America and the Caribbean.

Barcena was the founding director of the Earth Council in Costa Rica and served as director-general of the National Institute of Fisheries and the first vice minister of ecology while working for the government of Mexico. She also taught and researched on natural sciences.

Barcena also is a onetime protégé of Maurice Strong, the former special adviser to Annan who resigned his last U.N. post after it was revealed he had received about $1 million for a family-owned firm that originally came from Saddam Hussein and had ties to the Oil-for-Food scandal. She also has ties to outgoing Deputy Secretary-General Mark Malloch Brown.

Whoever is picked, some observers, like Jim Paul, executive director of the left-leaning Global Policy Forum — a group that monitors policy making at the United Nations — say the United States should not be allowed to keep an American in the management position. The choice of Burnham was an "egregious example" of the U.S. choice for that post simply being accepted, Paul claimed.

"It wasn't good that the United States got to name him but he was exceptionally qualified," Paul said of Connor.

Connor, a businessman, was appointed in 1994 and was a former chairman of Price Waterhouse.

"I'm afraid to tell you the idea that the secretary-general could pick people in the top posts based on their qualifications is a pipe dream," Paul said. "I'd love to think that's a possibility but the political constraints on the United Nations particularly heavy, particularly on the side of Washington. So the secretary-general doesn't have that much room to maneuver."

Nile Gardiner, a U.N. expert at the conservative Heritage Foundation, agreed that the secretary-general may have little actual say in who gets the position, but said the idea of someone from Annan's "discredited regime" getting the job is "worrying."

What's needed, he added, is someone who's serious about reform and not afraid to crack the whip and who is "willing to stamp out corruption and mismanagement within the United Nations," Gardiner said.

"The United States is the main driver of U.N. reform and so of course, it's in the U.S. interest to have an American in this position but that's not to say a non-American cannot do the job," Gardiner said. "I think it's a matter of finding the best person for this position — someone who is committed to real fundamental reform of the United Nations."

Gardiner said the actual selection process also needs to be more transparent and open.

"Often the best candidates for a position are not actually considered for the job," he said. "There is a secretive selection process in place which does not bode well for the future confidence in the United Nations — that's the central issue here. How does this person get selected for this post? What are her qualifications?"

For his part, Ban, while taking the oath of office, kept his cards close to vest, saying only that one of his core tasks "will be to breathe new life and inject renewed confidence into the sometimes weary secretariat" and to make "optimal use" of the staff's experience and expertise.

"At the same time, I will seek to set the highest ethical standard," he said. "The good name of the United Nations is one of its most valuable assets, but also one of its most vulnerable. The Charter calls on staff to uphold the highest levels of efficiency, competence and integrity, and I will seek to ensure to build a solid reputation for living up to that standard. … I will work to enhance morale, professionalism and accountability among staff members, which in turn will help us serve member states better and restore trust in the organization."

FOX News' David Lee Miller and Jonathan Wachtel contributed to this report.