Appealing to the international community, Gordon said funds for emergency rescue efforts were urgently needed.

"Millions are affected by this typhoon, and supplies are scarce," he added.

Rai, the 15th typhoon to hit the Philippines this year, made landfall on Siargao Island on Thursday, a popular tourist and surfing destination in the Caraga region of northeast Mindanao. It had initially packed winds of up to 260 kilometers (160 miles) per hour -- equivalent to a Category 5 storm.

Many preemptive evacuations and storm preparations began earlier in the week as the country began seeing heavy rain, but millions were still left vulnerable.

As Rai traveled west, it ripped down homes, trees and power cables in its path, bringing with it heavy rain, widespread flooding and landslides. Communities were destroyed and hundreds of thousands left homeless by the storm.

In nearby Surigao City, one of the worst-hit areas, survivors were seen pleading on the roads for food and water, surrounded by uprooted trees and electricity poles. Police were seen removing broken branches from the roads.

At least 4.1 million children have been affected by the typhoon, according to Save the Children. More than 16,000 families in hard-hit Caraga are estimated to be sheltering in cramped evacuation centers, it added.

Jerome Balinton, humanitarian manager of the organization, said the risk of disease spreading at these facilities is of "great concern."

Balinton expressed concern over the longer-term struggles that might arise from the typhoon's devastation, including food security and education issues.

"Although we haven't determined the extent of damage yet, there has been widespread destruction to schools," Balinton said. "Poorer, more vulnerable communities can be exposed to exploitation after this disaster."

The human-induced climate crisis is making typhoons, hurricanes and cyclones more intense and destructive, and the Philippines is one of the world's most climate-vulnerable nations.