On Monday, Chinese jets carried out "island encirclement patrols" around Taiwan, with state media showing pictures of bombers armed with cruise missiles.

Taiwan presidential spokesman Alex Huang said the defence ministry kept a close watch on the patrols and responded immediately and properly.

Mr Huang said: “Taiwan can ensure there are no concerns at all about national security, and people can rest assured.

"Such a raised military posture that may impact upon and harm regional peace and stability and cross-strait ties does not give a feeling of responsibility, and the international community does not look favourably upon this.”

He added that both sides of the narrow Taiwan Strait, which separates Taiwan from its giant neighbour, have a responsibility to protect peace and stability.

Taiwan denounced the rise in China's military deployments as irresponsible.

China considers self-ruled and democratic Taiwan to be its sacred territory and has never renounced the use of force to bring what it views as a wayward province under Chinese control.

Relations have soured considerably since Tsai Ing-wen, who leads Taiwan's independence-leaning Democratic Progressive Party, won presidential elections last year.

China suspects Tsai wants to declare the island's formal independence, a red line for Beijing. Tsai says she wants to maintain peace with China but will defend Taiwan's security.

Taiwan is well equipped with mostly US weapons but has been pressing for more advanced equipment to deal with what it sees as rising threat from China.

Although the United States has no formal ties with Taiwan it is bound by law to help it defend itself and is its main source of arms.

On Tuesday US President Donald Trump signed into law the National Defence Authorisation Act for the 2018 fiscal year, which authorises the possibility of mutual visits by navy vessels between Taiwan and the United States.

Such visits would be the first since the United States ended formal diplomatic relations with Taiwan in 1979 and established ties with Beijing.

It comes after a senior Chinese diplomat threatened to invade Taiwan if the state tries to gain independence or if a US warship visits the island.

Diplomat Li Kexin said at a Chinese embassy event in Washington on Friday that China would activate its Anti-Secession Law if the US sent navy ships to Taiwan.

According to Chinese media, Li said: “The day that a US Navy vessel arrives in Kaohsiung is the day that our People’s Liberation Army unifies Taiwan with military force.”

The Anti-Secession law allows it to use force on Taiwan if deemed necessary to prevent the island from gaining independence.

Influential Chinese tabloid the Global Times, published by the ruling Communist Party’s official People’s Daily, said China would never back down over Taiwan.

In an editorial, the paper said: “The Chinese mainland has never given up the option of Taiwan reunification by force, which is clear to people across the Taiwan Strait.

“Li’s words have sent a warning to Taiwan and drew a clear red line. If Taiwan attempts to hold an independence referendum or other activities in pursuit of de jure ‘Taiwan independence’, the PLA will undoubtedly take action.”

Earlier this year, the US issued a stark warning that it would not accept China’s militarisation of man-made islands in the South China Sea.

China's territorial claims in the South China Sea – through which about £3.9trillion in ship-borne trade passes each year – are contested by Brunei, Malaysia, the Philippines, Taiwan and Vietnam.