LONDON -- The World Health Organization routinely spends about $200 million a year on travel -- far more than what it doles out to fight some of the biggest problems in public health including AIDS, tuberculosis or malaria, according to internal documents obtained by The Associated Press.

As the cash-strapped U.N. health agency pleads for more money to fund its responses to health crises worldwide, it has also been struggling to get its own travel costs under control. Despite introducing new rules to try to curb its expansive travel budget, senior officials have complained internally that U.N. staffers are breaking the rules by booking perks like business class airplane tickets and rooms in five-star hotels.

Last year, WHO spent about $71 million on AIDS and hepatitis. On malaria, it spent $61 million. And to slow tuberculosis, WHO invested $59 million. Still, some health programs do get exceptional funding -- the agency spends about $450 million trying to wipe out polio every year.

In this Tuesday, April 7, 2015 file photo, World Health Organisation chief Margaret Chan, center, visits the Rungis international market to mark the World Health Day in Rungis, outside Paris, France. Michel Euler / AP

On a recent trip to Guinea, where WHO director-general Dr. Margaret Chan praised health workers in West Africa for triumphing over Ebola, Chan stayed in the biggest presidential suite at the Palm Camayenne hotel in Conakry. The suite has an advertised price of 900 euros, about $1,008, a night. The agency declined to say who picked up the tab, noting only that her hotels are sometimes paid for by the host country.

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But some say that sends the wrong message to the rest of the agency's 7,000 staffers.

"We don't trust people to do the right thing when it comes to travel," said Nick Jeffreys, WHO's director of finance, during an in-house seminar on accountability in September 2015 -- a video of which was obtained by the AP.

Despite WHO's numerous travel regulations, Jeffreys said staffers "can sometimes manipulate a little bit their travel." He said the agency couldn't be sure they were always booking the cheapest ticket or that the travel was even warranted.

"People don't always know what the right thing to do is," he said.

Ian Smith, executive director of Chan's office, said the chair of WHO's audit committee said the agency often did little to stop misbehavior.

In this Thursday, Oct. 2, 2014 file photo, Mercy Kennedy, 9, cries as community activists approach her outside her home on 72nd SKD Boulevard in Monrovia, Liberia, a day after her mother was taken away by an ambulance to an Ebola ward. Jerome Delay / AP

"We, as an organization, sometimes function as if rules are there to be broken and that exceptions are the rule rather than the norm," Smith said.

Earlier that year, a memorandum was sent to Chan and other top leaders with the subject, "ACTIONS TO CONTAIN TRAVEL COSTS" in all-caps. The memo reported that compliance with rules that travel be booked in advance was "very low" and also pointed out that WHO was under pressure from its member countries to save money.

Travel would always be necessary, the memo said, but "as an organization we must demonstrate that we are serious about managing this appropriately."

In a statement to the AP, the U.N. health agency said "the nature of WHO's work often requires WHO staff to travel" and said costs had been reduced 14 percent last year compared to the previous year -- although that year's total was exceptionally high due to the 2014 Ebola outbreak in West Africa.

But staffers are still openly ignoring the rules.

An internal analysis in March, obtained by the AP, found that only two of seven departments at WHO's Geneva headquarters met their targets, and concluded the compliance rate for booking travel in advance was between 28 and 59 percent.

Since 2013, WHO has paid out $803 million for travel. WHO's approximately $2 billion annual budget is drawn from the taxpayer-funded contributions of its 194 member countries, with the United States the largest contributor.

After he was elected, President Trump tweeted : "The UN has such great potential," but had become "just a club for people to get together, talk, and have a good time. So sad!"

Some health experts said while WHO's travel costs look out of place when compared to some of its disease budgets, that doesn't necessarily mean that travel expenses are inflated.

Michael Osterholm, an infectious diseases expert at the University of Minnesota, has frequently been flown to WHO meetings -- in economy -- on the agency's dime.

"This may just speak to how misplaced international priorities are, that WHO is getting so little for these disease programs," he said.

During the Ebola disaster in West Africa, WHO's travel costs spiked to $234 million. Although experts say on-the-ground help was critical, some question whether the agency couldn't have shaved costs so that more funds went to West Africa , where the three stricken countries couldn't even afford basics like protective boots, gloves and soap for endangered medical workers or body bags for the thousands who died.

This photo shows the five-star Palm Camayenne Hotel in Conakry, Guinea, on Saturday, May 20, 2017. Youssouf Bah / AP

Dr. Bruce Aylward, who directed WHO's outbreak response, racked up nearly $400,000 in travel expenses during the Ebola crisis, sometimes flying by helicopter to visit clinics instead of traveling by jeep over muddy roads, according to internal trip reports he filed.

Chan spent more than $370,000 in travel that year, as documented in a confidential 25-page analysis of WHO expenses that identified the agency's top 50 spenders. Aylward and Chan were first and second on that list. Three sources who asked not to be identified for fear of losing their jobs told the AP that Chan often flew in first class.

WHO said the travel policy, until February, "included the possibility for the (director-general) to fly first class." It said Chan flew business class and requested the policy be changed to eliminate the first-class option.

"There's a huge inequality between the people at the top who are getting helicopters and business class and everyone else who just has to make do," said Sophie Harman, an expert in global health politics at Queen Mary University in London.

Other international aid agencies, including Doctors Without Borders, explicitly forbid their staff from traveling in business class -- even having the charity's president fly in economy class, a spokeswoman said. With a staff of about 37,000 aid workers versus WHO's 7,000 staffers, Doctors Without Borders spends about $43 million on travel a year.

The U.S. Centers for Disease Control and Prevention would not provide its travel costs but said staffers are not allowed to fly business class unless they have a medical condition that warrants it. The U.N. children's agency UNICEF, which has about 13,000 staffers, said it spent $140 million on global travel in 2016.

"When you spend the kind of money WHO is spending on travel, you have to be able to justify it," said Dr. Ashish Jha, director of the Global Health Institute at Harvard University. "I can't think of any justification for ever flying first class."

Jha warned that WHO's travel spending could have significant consequences for fundraising. Several weeks ago, WHO asked for about $100 million to save people in Somalia from an ongoing drought. In April, it requested $126 million to stop the humanitarian catastrophe in Yemen.

"If WHO is not being as lean as possible, it's going to be hard to remain credible when they make their next funding appeal," Jha said.