China on Monday said it is keeping a close watch on reports of US House Speaker Nancy Pelosi's planned visit to Taiwan and warned of a "resolute response" by its military and "strong countermeasures" if she went ahead with the trip to Taipei.Ms Pelosi is expected to visit

Taiwan, CNN quoted senior Taiwanese and US officials as saying despite warnings from the Biden administration officials, who are worried about China's response to such a high-profile visit.

China views Taiwan as a breakaway province that must become a part of the country. Beijing has not ruled out the possible use of force to achieve the reunification of Taiwan with the mainland in the future.

Ms Pelosi, 82, confirmed on Sunday she will lead a congressional delegation to Singapore, Malaysia, South Korea and Japan but was conspicuously silent about a possible stopover at Taiwan, the self-governing island that China claims as part of its mainland.

While there have been no official announcements, local media in Taiwan reported that Ms Pelosi will arrive on Tuesday night, becoming the highest-ranking elected US official to visit in more than 25 years.

Taiwanese media quoted officials as saying that Ms Pelosi would arrive in Taipei after visiting Malaysia and spend the night.

Chinese President Xi Jinping spoke of a fiery response to the visit in his phone call with his US counterpart Joe Biden last Thursday, stating that "those who play with fire will perish by it."

Reacting to the reports of her visit to Taiwan, Chinese Foreign Ministry spokesman Zhao Lijian told a media briefing here "we are closely following the itinerary of Speaker Pelosi" and (we would) give a resolute response if she went ahead with the visit.

"As for what those measures will be, let's see what happens if she actually goes," he said. "We want to once again make it clear to the US side that the Chinese side is fully prepared for any eventuality and that the People's Liberation Army of China will never sit idly by, and we will make a resolute response and take strong countermeasures to uphold China's sovereignty and territorial integrity."

The Chinese side has repeatedly made clear to the US side China's serious concern over Speaker Pelosi's potential visit to Taiwan and its firm opposition to the visit, he said.

"We have been stressing that such a visit would lead to serious consequences. As President Xi Jinping stressed to US President Joe Biden in their phone call, the position of the Chinese government and people on the Taiwan question is consistent, and resolutely safeguarding China's national sovereignty and territorial integrity is the firm will of the more than 1.4 billion Chinese people," he said.

"The public opinion cannot be defied. Those who play with fire will perish by it. We believe that the US side is fully aware of China's strong and clear message," he said.

"What the US should do is to abide by the 'One China' principle and the stipulations of the three Sino-US joint communiques, fulfill President Biden's commitment of not supporting Taiwan's independence and not arrange for a visit by Speaker Pelosi to Taiwan," he said.

Ms Pelosi heading a US Congressional delegation on Monday held talks with officials in Singapore at the start of her Asian tour while speculation remained rife about her Taiwan visit.

CNN quoted a US official as saying that Defence Department officials are working around the clock on monitoring any Chinese movements in the region and securing a plan to keep her safe.

Taiwan will give Ms Pelosi a low-profile but high-level reception if the senior Democratic Party leader defies Beijing's repeated warnings and makes an unannounced visit to the island, Hong Kong-based South China Morning Post reported.

Regardless of the capacity in which Pelosi travels to Taiwan, she will be given the highest official reception, meeting Taiwanese President Tsai Ing-wen and receiving treatment reserved for top foreign dignitaries,the report quoted analysts as saying.

But they said Taipei would try to keep the trip low-profile to avoid further antagonising Beijing, which again sounded a warning against the potential visit.

The Chinese military earlier said it will not sit back if Ms Pelosi went ahead with the visit.

Tan Kefei, a spokesperson for China's Ministry of National Defence said, "If Speaker Pelosi visits Taiwan, it would seriously violate the 'One China' principle and the stipulations in the three China-US joint communiques, seriously harm China's sovereignty and territorial integrity, and seriously damage the political foundation of China-US relations."

"It will inevitably result in extremely serious damage to the relations between the two countries and the two militaries, and lead to further escalation of the tensions across the Taiwan Strait," he said.