The fast-moving Kong-rey was expected to make landfall within hours along the lightly populated, mountainous east coast where many people have been evacuated.

Kong-rey was packing wind gusts of nearly 260 kilometres per hour (161 miles per hour), according to the US Joint Typhoon Warning Center.

The storm is currently more powerful than Typhoon Gaemi, which was the strongest typhoon to hit Taiwan in eight years when it made landfall in July.

"With the typhoon approaching, we should beware of the strong winds near the centre," Chu Mei-lin from the state weather forecaster, Central Weather Administration, told a briefing.

"Its impact on the entire Taiwan will be quite severe."

Work and schools across Taiwan were suspended on Thursday as people hunkered down for the storm.

The streets of Taipei were largely deserted as bursts of heavy rain and wind battered the capital.

At least 27 people have been injured in the wild weather, with trees being knocked down and four mudslides recorded, the National Fire Agency said Thursday, without providing details.

Kong-rey was travelling at 28 kilometres per hour (16 miles per hour) as it swept towards Hualien and Taitung counties, whipping up waves of up to 10 metres high.

The storm was expected to slow after hitting land and then move across the island before exiting over the Taiwan Strait in the evening, Chu said.

With a radius of 320 kilometres, Kong-rey was on track to be the most expansive severe typhoon to make landfall in nearly 30 years, the Central Weather Administration said earlier.

More than a metre of rain could fall in the hardest-hit areas along the east coast by Friday as the seasonal monsoon also drenched the island of 23 million people earlier in the week, prompting warnings of landslides.

Authorities began evacuations on Wednesday in eight counties and cities, including Yilan, Hualien and Taitung, according to the National Fire Agency.

More than 6,200 people had been evacuated from their homes by the evening.

Scientists have warned climate change is increasing the intensity of storms, leading to heavier rains and flash floods and stronger gusts.

Kong-rey will be the third typhoon to hit Taiwan since July.

Gaemi killed at least 10 people, injured hundreds and triggered widespread flooding in the southern seaport of Kaohsiung.

That was followed in early October by Krathon, which killed at least four people and injured hundreds, triggering mudslides, flooding and record-strong gusts.