The island is self-ruled, though Beijing considers it to be a breakaway province that it will eventually unite with. Tensions over its international status were last week stoked when a leading US Democrat visited its capital, Taipei.
This prompted a range of military drills from Beijing, which are now said to have finished.
Chinese Foreign Minister Wang Yi insisted that Nancy Pelosi was “violating China’s sovereignty under the guise of so-called democracy”.
As tensions continue to rise, officials have now warned Xi Jinping could be planning to take Taiwan quicker than the West could respond.
Diplomatic sources have told the Telegraph Beijing could launch a “lightning-fast 48-hour offensive” against the island.
They are understood to have learnt from the “special military operation” in Ukraine that the West took at least two days to respond and that this period offers “the crucial window of time when irreversible gains can be made”.
Hong Kong Watch Chief Executive and Co-Founder Benedict Rogers insisted the West must take action to prevent China from taking this course of action.
He wrote in a post on Twitter: “We must not let this happen.
“We must be ready.
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He wrote: “If the west sanctions China like they did with Russia, we’d see financial chaos off the richter scale.
“China is a beast, just imagine sanctions on most products ‘Made in China’, which is the majority of products in your home. Inflation would go nuts.”
Diplomats did, however, tell the Telegraph that any form of invasion is unlikely to take place in the immediate months ahead.
Sidharth Kaushal of think tank RUSI noted that “the PLA [that is, the ‘People’s Liberation Army’ of China] is still an evolving force”.
He added that the force would need time to prepare for such action given the “realistic possibility of war with the US” in the wake of an invasion.
Mr Kaushal said: “It’s probably unachievable right now.
“There are some substantial risks for China.”