China's government on Tuesday warned that it would take "forceful measures" if US House of Representatives speaker Nancy Pelosi visited Taiwan, after the Financial Times said she would go to the Chinese-claimed island next month.

Pelosi and her delegation will also visit Indonesia, Japan, Malaysia and Singapore, and spend time in Hawaii at the headquarters of US Indo-Pacific command, the London paper added, citing people familiar with the matter.

The US State Department did not immediately respond to a Reuters request for comment. Taiwan's Foreign Ministry said it has "not received relevant information" about any visit.

Asked about the report, Drew Hammill, Pelosi's deputy chief of staff, said, "We do not confirm or deny international travel in advance due to longstanding security protocols."

The Democratic leader's visit to Taiwan had been postponed from April, after she tested positive for Covid-19. At the time, China said such a visit would severely affect Chinese-US relations.

Speaking in Beijing, Chinese Foreign Ministry spokesman Zhao Lijian said any visit by Pelosi would "seriously undermine China's sovereignty and territorial integrity".

"If the US side obstinately clings to this course, China will definitely take resolute and forceful measures to firmly defend its national sovereignty and territorial integrity," he said. "The United States must be fully responsible for all the consequences caused by this."

Taiwan faces mounting pressure from China, which considers the democratically governed island its own territory. The issue is a constant irritant in ties between Beijing and Washington.

Taiwan, however, has been heartened by continued support offered by US President Joe Biden's administration, which has repeatedly spoken of its "rock-solid" commitment to the island.

Pelosi, a long-time critic of China, held an online meeting with Taiwanese Vice President William Lai in January as he wrapped up a visit to the United States and Honduras.

‘White House expresses concern’

The White House had expressed concern about the Pelosi trip, the Financial Times said, citing three people familiar with the situation.

There were divisions in the Democratic US administration over whether Pelosi should visit Taiwan, the FT quoted two sources as saying.

Some officials believed it had been easier to justify a visit in April, as that was just after the start of Russia's invasion of Ukraine, it added.

A spokesperson for the US National Security Council would not comment on "travel that the Speaker's office itself has not announced," and reiterated that the United States remains committed to its One China policy.

Separately, the US Navy's 7th Fleet said the Arleigh Burke-class destroyer USS Benfold conducted a routine Taiwan Strait transit on Tuesday, "through international waters in accordance with international law."

"The ship transited through a corridor in the Strait that is beyond the territorial sea of any coastal State," it said in a statement.

The United States has been carrying out such voyages through the stretch of water separating Taiwan and China about once a month. This has angered Beijing, which views them as a sign of support for the island.

This month, China sent fighters across the Taiwan Strait's median line, an action Taiwan described as a provocation. The incident came during a visit to Taipei by Senator Rick Scott, a Republican member of the US Senate Armed Services Committee.

On Monday, China asked the United States to immediately cancel a potential sale of military technical assistance to Taiwan worth an estimated US$108 million.

- Reuters