Philippine authorities are preparing to move thousands of people amid fears of tidal surges, flashfloods and landslides from an incoming typhoon.

Typhoon Maysak was packing maximum sustained winds of 150 kilometres per hour and gusts of up to 185km/h as it neared the country's eastern coast, the weather bureau said.

The cyclone has weakened from sustained winds of 215km/h and gusts of 250km/h.

"Local government units and police are prepared to enforce pre-emptive or forced evacuations if necessary to ensure the safety of everyone," said Interior Undersecretary Austere Panadero.

"We encourage the public to heed the orders of the authorities," he added.

Maysak was moving west-northwest at 17km/h.

It is expected to start bringing rain and strong winds by Saturday and make landfall on Sunday, the weather bureau said.