UNITED NATIONS, N.Y. — In his strongest statement since a deadly cholera epidemic erupted in Haiti almost four years ago, the head of the United Nations said the global body bears “a moral responsibility” to help the Caribbean nation end the outbreak.

U.N. Secretary General Ban Ki-moon made the declaration in an exclusive interview with the Miami Herald as he prepared to visit Haiti, where he will travel to the region where the contamination happened and meet with families hard hit by cholera. Detected 10 months after Haiti’s devastating Jan. 12, 2010, earthquake, the waterborne disease has killed 8,563 people and infected 704,245.

Since then, the U.N. has refused to admit responsibility for the outbreak, which scientific evidence and its own independent panel of experts suggested was brought to Haiti by Nepalese peacekeepers stationed at a military base in the Central Plateau region.

Nor has the world body offered an apology, which victims and their families are seeking along with compensation, in three separate lawsuits filed in United States courts.

“Regardless of what the legal implication may be, as the secretary general of the United Nations and as a person, I feel very sad,” Ban said. “I believe that the international community, including the United Nations, has a moral responsibility to help the Haitian people stem the further spread of this cholera epidemic.”

Ban’s statement on the eve of his arrival Monday comes after Haitian Prime Minister Laurent Lamothe called on the U.N. last fall to take “moral responsibility” for cholera, and after the U.N.’s independent human rights expert on Haiti earlier this year demanded “full compensation” for cholera victims. In the Feb. 7 report, Gustavo Gallon criticized the silence while publicly disagreeing with the U.N., which has rejected compensation and invoked immunity in the legal cases.

“The diplomatic difficulties surrounding this issue must be overcome to ensure the Haitian people that the epidemic can be stopped in the shortest possible time frame and pay full compensation for the damages suffered,” Gallon said.

By the U.N.’s own admission, foreign donors have been slow to contribute to a $2.2 billion, 10-year cholera-elimination campaign that Ban launched in December 2012 with the presidents of Haiti and the neighboring Dominican Republic. The organization has struggled even to raise an initial $400 million it says is needed in the first two years to contain the epidemic and build clean water and sanitation infrastructure.

Getting donors to deliver the money will be a key issue during his visit, Ban said, noting that Haitians “have suffered a lot” under the world’s worst cholera epidemic. The way to prevent a repeat of cholera, he said, is to help Haiti address the root cause: poor sanitation.

“The international community has been struggling to overcome this global financial difficulty, and we have so many crises happening at the same time around the world,” said Ban. “That is one reason why we have not been able to effectively mobilize.”

While the humanitarian crises have also put pressure on Ban to reduce the size of the peacekeeping mission in Haiti, observers say they believe donors are holding onto the purse strings for other reasons.

Some blame Haiti fatigue, which has some donors quietly reassessing and reducing financial aid to the country. Others say another factor is the U.N.’s refusal to accept that leaking sewage pipes at its base were to blame for cholera’s spread.

There is also Haiti’s political gridlock, which continues to threaten the staging of long-overdue local and legislative elections in October.

With every disagreement, observers say, Haiti’s politicians get further from reaching a compromise for the balloting.

“My political message to Haitian leaders, government and parliamentary leaders will be that it’s crucially important that this election be held as agreed and scheduled in October,” Ban said.

Helping Haitians break the gridlock, and the future of the U.N. Stabilization Mission’s (MINUSTAH) 5,000 blue helmets and 2,600 police officers in Haiti will also top his agenda, he said.

“Haiti cannot afford drifting without . . . a full Senate, a full Assembly and executive branch,” said Mark Schneider, senior vice president for the International Crisis Group, which monitors Haiti. “He needs to play the convening role in bringing the still very widely divided political actors together to produce a compromise that will help Haiti reach parliamentary elections this fall.”

While Schneider welcomes Ban’s visit and his acknowledgment of “the debt owed to the Haitian people as a result of the introduction of cholera,” he noted the U.N.’s failure to apologize for cholera has caused it to be the target of criticism, including growing calls for its departure.

“The U.N. and MINUSTAH have played a fundamental role in helping to deal with the aftermath of the earthquake, to help build Haitian institutions, and continues to play a critical role,” Schneider said. “But with respect to the issue of cholera, they have simply failed to recognize how deeply this has hurt their image in Haiti.”

Brian Concannon, an attorney with the Boston-based rights group, the Institute for Justice and Democracy in Haiti, said he isn’t surprised by donors’ reluctance to aid the U.N.’s anti-cholera campaign.

“Certainly the U.N.’s refusal to accept responsibility and comply with its legal obligations undermines its mission to promote the rule of law in Haiti and elsewhere,” said Concannon, whose group was the first to file claims on behalf of 5,000 cholera victims and their families.

“Somewhere this afternoon, a police trainer is giving Haitian police officers a lecture about how they need to sacrifice their personal and friends’ interests and respect the rule of law so that Haiti can advance,” he said. “The trainees are looking at the logo on her/his shirt and laughing.”

Longtime Haiti observer Robert Maguire said Haiti’s current political reality also cannot be dismissed in tackling the cholera crisis.

“Does the fact that Haiti is once again manufacturing a political crisis discourage international donors from solving what is more of a social crisis?” said Maguire, director of the Latin American and Hemispheric Studies Program at George Washington University’s Elliott School of International Affairs in Washington, D.C. “If Haiti didn’t have elections that are two years delayed, constant provocation, these eternal disputes and gridlock, wouldn’t that perhaps encourage international donors to be more generous with Haiti?”

Cholera aside, Maguire said Ban serves an important purpose.

“The United Nations remains committed to leaving behind in Haiti an effective and independent police force. That is probably among the most salient objectives of MINUSTAH,” Maguire said about the force, whose strength and ability to secure Haiti is viewed as a key benchmark for the U.N.’s eventual departure.

“Over the past three years, there has been some discomfort about whether there could be political erosion in Haiti and the independence of the police force,” he said. “This is one of MINUSTAH’s objectives in maintaining a presence, mitigating any tendencies in Haiti to politicize the police force. I think that is quite clear.”

In June, the U.N. marked a decade in Haiti. Even as military troops quietly pull out of some regions, leaving security to the local police, questions and uncertainty remain about the mission’s future configuration.

“We are not going to completely withdraw,” Ban said from his 38th-floor office at the U.N.’s New York headquarters. “We are going to try and reduce our soldiers so that the Haitian government and people can really enhance this capacity and stand on their own.”

Ban said he is encouraged, for instance, by the progress the government has made in building up the 11,000-member Haitian National Police force. But there is more work to do, he acknowledged.

“The Haitian people and government have made considerable progress, first of all in ensuring stability, of course with the help of MINUSTAH, and enhancing the [national police],” he said. “But at the same time, we hope there could be more progress in justice and accountability areas. Common, ordinary people should be able to get some support and protection from the government.”