China's President Xi Jinping (front right) speaks during the opening session of the 20th Chinese Communist Party's Congress at the Great Hall of the People in Beijing
China's President Xi Jinping (front right) speaks during the opening session of the 20th Chinese Communist Party's Congress at the Great Hall of the People in Beijing AFP

Beijing wants to seize Taiwan "on a much faster timeline" than previously considered, US Secretary of State Antony Blinken said Monday, warning that President Xi Jinping was leading China in a more aggressive direction.

Xi is on the cusp of securing a third five-year term at the helm of the world's most populous nation, delivering a landmark Communist Party Congress speech on Sunday that hailed his decade in power and restated his vow to one day "reunify", or forcefully take, Taiwan.

"We've seen a very different China emerge in recent years under Xi Jinping's leadership," Blinken told a forum at Stanford University with former secretary of state Condoleezza Rice.

"It is more repressive at home; it's more aggressive abroad. And in many instances that poses a challenge to our own interests as well as to our own values," he added.

Blinken accused Xi of "creating tremendous tension" by changing the approach toward self-ruled Taiwan, which China's Communist Party has never controlled but claims as its own.

He said China had made a "fundamental decision that the status quo was no longer acceptable, and that Beijing was determined to pursue reunification on a much faster timeline", though he gave no hard estimate or date.

Senior US military figures have previously sounded the alarm that China has expanded its military forces to the point where it could soon have the capability to pull off an invasion of Taiwan.

China's stance has long been that it seeks "peaceful reunification" with Taiwan but reserves the right to use force if necessary, especially if the island ever formally declares independence.

But the rhetoric and actions towards Taiwan have become more pronounced under Xi, China's most assertive leader in a generation.

He has tied taking Taiwan to his landmark "great rejuvenation of the Chinese nation" and has previously said the goal of reunification cannot continue to be passed indefinitely from generation to generation.

In Sunday's speech he repeated similar themes, saying the "wheels of history are rolling on towards China's reunification" and that "we reserve the option of taking all measures necessary".

Russia's recent invasion of Ukraine, which China has not condemned, has also raised fears that Beijing might try something similar against Taiwan's 23 million people.

Ties between Washington and Beijing have been at a decade-low ebb under both the administrations of Donald Trump and his successor Joe Biden, over a range of issues from trade to security and human rights.

But Blinken said the world's two largest economies should be willing to cooperate on shared interests.

He said the world "fundamentally expects" the two powers to work together on climate change, global health and possibly drug trafficking.

Beijing "just has to be responsive to demand signals that it's getting from countries around the world to be a positive actor, not a negative actor, on issues that concern them".

China cut cooperation with the United States on climate change and drug trafficking in August as part of its protest against a visit to Taiwan by US House Speaker Nancy Pelosi, which also saw Beijing launch its biggest military drills yet around the island.

Xi is widely expected to meet President Biden on the sidelines of a Group of 20 summit next month in Bali, their first meeting since the US leader took office.

Blinken made his comments on China at Stanford University
Blinken made his comments on China at Stanford University AFP