Chinese media reports troop movement in Taiwan Straits as Nancy Pelosi lands in Taipei

China's official media reported air and ground movement of troops in Taiwan Straits - the waters that separate China and Taiwan - as US House Speaker Nancy Pelosi landed in Taipei on Tuesday disregarding Beijing's stern warnings.

Pelosi landed in Taipei on Tuesday night, according to the television footage shown by US networks. She is the highest-ranking US official to visit Taiwan in 25 years.

As the Taiwan media reported her arrival, the Chinese official social media reported large scale military movement in the Taiwan Straits.

"PLA Air Force's Su-35 fighter jet(s) crossing the Taiwan Straits," State-run China Daily reported, citing a social media account.

Postings in the Chinese social media Weibo, akin to Twitter, also showed footage of armoured vehicles on the move in the southern Chinese city of Xiamen - a port city on China's southeast coast facing Taiwan.

Another tweet by China Daily said the People's Liberation Army's Eastern Theatre Command said its forces are on high alert and will "engage the enemy on orders".

Beijing routinely protests any foreign dignitaries' visits to Taiwan, which claims it as its own and firmly insists all countries follow the One China policy acknowledging that the breakaway province is part of its mainland.

In Beijing, the Chinese foreign ministry said the US would pay the price if Pelosi went to Taiwan.

"The US side will bear the responsibility and pay the price for undermining China's sovereign security interests," Assistant Foreign Minister and foreign ministry spokeswoman Hua Chunying told a media briefing here on Tuesday and reiterated that Beijing would take strong measures in response to Pelosi's visit.

"Faced with reckless US disregard of China's repeated and serious representations, any countermeasures taken by the Chinese side will be justified and necessary, which is also the right of any independent and sovereign country," Hua said, responding to questions on what possible actions China would take to deter her from going to Taipei.