US House Speaker Nancy Pelosi said that Washington cannot allow Beijing to establish a new normal in Taiwan with its provocative drills and warplane incursions in the Taiwan Straits, in retaliation to her high-profile visit to the self-ruled island last week.

"What we saw with China is that they were trying to establish sort of a new normal. And we just can't let that happen," Pelosi told a news conference on Wednesday after her trip to Asia.

China on Wednesday announced that it has "successfully completed" its week-long and unprecedented military drills that have essentially encircled Taiwan, warning that Beijing will organise regular combat patrols as a new normal to enforce its one-China policy.

Initially, the People's Liberation Army announced the war games in the busy Taiwan Strait from August 4 to 7, the day after Pelosi who is the highest-ranking US leader to have visited Taiwan in 25 years, left Taipei after high-level meetings.

It later kept extending them, keeping the breakaway island on tenterhooks.

The Chinese military exercises involved hundreds of warplanes, dozens of naval ships, including an aircraft carrier group with nuclear submarine in tow, amid assertions by the official media here that such war games in the busy Taiwan Strait will be a new normal.

We didn't go there to talk about China. We went there to praise Taiwan. And we went there to show our friendship to say, China cannot isolate Taiwan,' Pelosi asserted.

The visit delivered a clear statement that America's commitment to a free and open Indo-Pacific is unshakeable, Pelosi noted.

She said bilateral discussions centred around seizing opportunities and addressing shared challenges, including upholding the democracy in the face of autocracy, fostering robust economic growth, including through the Indo-Pacific Economic Framework and in governance, responding to COVID-19 and climate crisis.

House Foreign Affairs Committee chairman Gregory Meeks told reporters that Pelosi's visit to Taiwan illustrated that no matter what Chinese President Xi Jinping said, the US was going to stand by its friends and allies.

Indian American Congressman Raja Krishnamoorthi, who was part of the Congressional delegation to Taiwan, was also present at the news conference.

He said the delegation discussed the backlog of the pending arms sales to Taiwan.

The delegation also visited Singapore, Malaysia, Taiwan, South Korea and Japan.