The new study suggests adding a category 6 for "mega-hurricanes" with winds of more than 310 km/h, as climate change makes such extreme storms more likely.
The Philippine Defense Minister has vowed to defend the country's sovereignty against threats of secession from the southern island of Mindanao by former President Rodrigo Duterte.
Vietnam and the Philippines signed a maritime cooperation agreement on Tuesday to help better manage conflicts amid threats from China in the South China Sea.
CNN Philippines, which opened in 2015, will cease its news and production activities across all media platforms on January 31, laying off 300 employees.
