One of Philippines' most popular tourist destinations will be off-limits to visitors in a few weeks.

The entire island of Boracay will be closed to visitors from Apr. 26, so that it can receive a massive clean-up of dumped sewage and upgrades to its drainage systems, a spokesperson for President Rodrigo Duterte confirmed Thursday. It will be shut for a maximum of six months.

Duterte, who has been criticised for his stance on human rights, had previously described the island as a "cesspool," and was concerned the island could be turned into a "fishpond or a sewer pool" if its environmental needs weren't addressed.

Boracay had 2 million visitors in 2017, a number that was described as moving toward the "alarming" by the country's department of environment, as the island struggles with sustainable development and waste.

The island is very much dependent on tourism. Up to 36,000 jobs ranging from hotel workers to street vendors could be lost in the shutdown, with authorities rejecting pleas by locals to consider a partial closure of the island.

Tourists pose for photos along a beach on Boracay island. Image: -/AFP/Getty Images

The president's spokesperson argued that Boracay's environmental rehabilitation has to be completed in total.

"We were expecting some sort of compromise between a partial or total closure or at least given more time to adjust to a closure, but I guess the president made up his mind and we’re taken aback by it. We’re a bit depressed right now in the industry," Jose Clemente III, president of the Tourism Congress of the Philippines, told ABS-CBN.

"If given the opportunity, yes, we would like to present our case. The private sector did not have a face-to-face dialogue with the president. We were doing it through the various agencies. Unfortunately, I guess this is the result of the recommendations of those agencies."

The island generates 90 to 115 tonnes of garbage a day, but current infrastructure only allows for 30 tonnes to be removed. Authorities say they've also discovered illegal, "hidden" pipes on the island used to dispose waste.

"Boracay island is seen as a major, world-class tourist destination," Epimaco Densing, assistant secretary of the Philippines' interior department, told reporters.

"Yet in fact we're not able to address the major issue that it is not in terms of public safety, public order, road systems and of course, the issue of environmental degradation."

Frederick Alegre, a secretary from the country's tourism department, said his department is still calculating the financial cost of the closure, but stressed it was "being done to sustain and save Boracay." He said the island is the first of several Filipino tourist destinations that will be looked at.

Boracay's closure comes after Thai authorities decided last week to close Maya Bay, also for a period of six months, due to the impacts of tourism on the beach's environment.