Typhoon Mangkhut has been classified as a 'super typhoon' and is due to hit Philippine's northeast Cagayan province on Saturday.
Thousands of people are being evacuated from the path of the most powerful typhoon to hit the Philippines this year.
Mangkhut is forecast to hit the northeastern Cagayan province, where over four million people live, early on Saturday local time.
On Friday it was about 450km away in the Pacific with sustained winds of 205km/h and gusts of up to 255km/h, Philippine forecasters say.
Typhoon Mangkhut has been categorised as a super typhoon with powerful wind and gusts equivalent to a category 5 Atlantic hurricane.
Schools have been closed and bulldozers are on the ready for landslides with rescuers and troops on full alert.
With a massive rain cloud band 900km wide, combined with seasonal monsoon rains, the typhoon could bring heavy to intense rains that could set off landslides and flash floods, the forecasters said.
Storm warnings have been raised in 25 provinces across the main northern island of Luzon, restricting sea and air travel.
Office of Civil Defense chief Ricardo Jalad told an emergency meeting led by President Rodrigo Duterte that about 4.2 million people in Cagayan, nearby Isabela province and outlying regions are vulnerable to the most destructive effects near the typhoon's 125km-wide eye.
Nearly 48,000 houses in those high-risk areas are made of light materials and vulnerable to Mangkhut's ferocious winds.