MANILA - Typhoon Nari gained strength as it swept towards the Philippines on Friday, prompting warnings of more brutal weather for tens of millions of people living in around the flood-prone capital.
Nari forced US Secretary of State John Kerry on Thursday to cancel a visit to Manila, and weather forecasters said it had since been upgraded from a tropical storm to a typhoon as its wind gusts increased to 160 kilometres (100 miles) an hour.
Nari was expected to hit farming regions on the east coast of the main island of Luzon late on Friday night, with "heavy to intense" rain forecast across its 500-kilometre-wide footprint, the state weather service said.
Manila is about 135 kilometres south of where the eye of the storm is expected to make landfall, and government weather forecaster Bernie Belen said the capital would likely again endure floods.
"Even without a storm, heavy rains can cause floods in Manila. How much more when there is a typhoon?" Belen told AFP.
Heavy rains are expected to persist across much of the main island of Luzon throughout Saturday as Nari travels west, before blowing out into the South China Sea in the evening.
The Philippines is hit by about 20 major storms or typhoons each year that occur mainly between June and October.
Manila, a sprawling coastal megacity of more than 12 million people, regularly sees water climb up into homes during the rainy season.
While government authorities say the intensity of storms is believed to be increasing because of climate change, chaotic urban planning and clogged waterways also exacerbate the floods.
The deadliest recent flooding in Manila occurred in 2009, when 460 people died after Tropical Storm Ketsana left more than 80 per cent of the capital under water.
The strongest storm to hit the Philippines this year was Typhoon Usagi, which had winds reaching 195 kilometres an hour and killed about 30 people late last month.
Kerry was scheduled to visit Manila on Friday and Saturday, ending an Asian tour that had taken him to Indonesia, Brunei and Malaysia. But he cancelled on Thursday, citing the dangers of Nari.