The People's Liberation Army on Thursday launched live-fire military drills in multiple zones encircling Taiwan in a show of force following a visit to Taipei by US House Speaker Nancy Pelosi.

State media reported that the exercises are to end at noon on Sunday.

"Six major areas around the island have been selected for this actual combat exercise and during this period, relevant ships and aircraft should not enter the relevant waters and airspaces," broadcaster CCTV reported.

Taiwan authorities also issued warnings to ships to avoid the areas being used for the drills.

A Global Times report cited military analysts as saying that the exercises – at some points within 20 kilometres of the island’s shore – were "unprecedented".

"This is the first time the PLA will launch live long-range artillery across the Taiwan Straits," the newspaper said, referring to the People's Liberation Army.

Drills taking place since Tuesday have set the stage for the exercises, with the Xinhua news agency reporting they had simulated a "joint blockade" of Taiwan.

The Foreign Ministry has said the planned exercises are "necessary and just", pinning the blame for the escalation squarely on the United States and its allies.

"In the current struggle surrounding Pelosi's Taiwan visit, the United States are the provocateurs, China is the victim," foreign ministry spokeswoman Hua Chunying told a regular briefing on Wednesday.

"The joint provocation by the US and Taiwan came first, China's just defence came after," she added.

Pelosi left Taipei on Wednesday after a less than 24-hour visit that sparked a furious reaction from Beijing, which vowed punishment for those that had offended the nation. (Agencies)