The violent Super Typhoon Mangkhut now has sustained winds of 130mph (200km/h) - the equivalent of a Category 4 hurricane and the winds of Hurricane Florence which is racing towards the south-east coast of the US.
Super Typhoon Manghkut is on track to hit the northern Philippines with its strongest winds on Friday before striking Taiwan and then possibly heading towards Hong Kong and mainland China.
The Hong Kong Observatory said Mangkhut is expected to reach China's southeastern coast on Sunday.
The Philippine Red Cross estimates three million Filipinos live in the direct path of Mangkhut, communications officer Mary Joy Evalarosa told AFP. Mangkhut now has 200 kph center winds and 245 kph gusts.
Cagayan Gov. Manuel Mamba said by telephone that northern coastal and island villages in the typhoon's projected path will begin evacuating residents on Thursday ahead of the expected onslaught. He has already ordered schools and government offices to close.
The typhoon, the 15 to hit the country this year and forecasted to be the strongest so far, is expected to bring heavy rains on Thursday before it makes landfall early Saturday.
"I'm stressing that this one is very different, this is more complicated because of possible storm surges", Mamba said, referring to giant waves whipped inland by a typhoon.
Weather specialist Aldczar Aurelio of the Philippine Atmospheric, Geophysical and Astronomical Services Administration (Pagasa) said Tropical Depression "Neneng" brought light to moderate rains over the Batanes and Calayan group of islands on Monday as it formed 22 kilometers north of capital town of Basco.
A missile test aboard a navy ship to be attended by president Rodrigo Duterte off northern Bataan province was cancelled due to the approaching typhoon.
The country's deadliest on record is Super Typhoon Haiyan, which left more than 7,350 people dead or missing across the central Philippines in November 2013.
An average of 20 typhoons and storms lash the Philippines each year, killing hundreds of people and leaving millions in near-perpetual poverty.