U.S. President Joe Biden. (Getty/Kyodo)

U.S. President Joe Biden on Monday expressed concern over China's increased military activities around Taiwan in the wake of U.S. House of Representatives Speaker Nancy Pelosi's visit to the self-ruled island, but indicated he does not expect further moves by Beijing to heighten tensions.

What concerns him is that China is "moving as much as they are," Biden told reporters in Delaware, adding, "But I don't think they're going to do anything more."

A Pentagon official denied that the latest development has changed an assessment that China is not likely to attempt to take over Taiwan militarily within the next two years, a view voiced by the U.S. military's top officer Mark Milley last year.

Asked whether the assessment has been affected, Colin Kahl, undersecretary of defense for policy, said, "No."

The New York Times reported in late July, prior to Pelosi's visit to Taiwan, that the Biden administration has grown anxious about China's statements and actions regarding Taiwan, with some officials fearing that Chinese leaders "might try to move against the self-governing island over the next year and a half."

Beijing may try to cut off access to all or part of the Taiwan Strait, through which U.S. naval ships regularly pass, it said.

China's military exercises near Taiwan in response to Pelosi's visit last week have involved ballistic missile launches, raising tensions in the region. Some of the missiles from China have fallen into Japan's exclusive economic zone, something that has not happened before, according to the Japanese government.

Pelosi made the visit to Taiwan to show support for the democratic island facing pressure from China, which views Taiwan as a renegade province awaiting reunification with the mainland, by force if necessary.

Photo posted by the Chinese military's Eastern Theater Command on social media platform Weibo on Aug. 3, 2022, shows a military exercise in progress. (Kyodo)

It was the first such trip by a U.S. House speaker in 25 years, and has infuriated Beijing, which has opposed anything it views as official interaction between the United States and the territory.

Biden administration officials have been criticizing Beijing's reaction to the visit, including the large-scale military drill and the suspension of bilateral engagements on climate change and other issues.

But the administration has also made clear that it has no intention to see the latest development spiral into a crisis with China.

"Clearly, the PRC is trying to coerce Taiwan. Clearly, they're trying to coerce the international community. And all I'll say is we're not going to take the bait," Kahl told a press conference, using the acronym of the People's Republic of China, the country's official name.

The United States changed its diplomatic recognition from Taipei to Beijing in 1979, but has kept up unofficial relations with the island and supplies it with arms and spare military parts to help it maintain sufficient self-defense capabilities.