BEIJING – China on Tuesday (Aug 2) said it was in communication with the United States over House Speaker Nancy Pelosi’s expected visit to Taiwan, warning that Washington will “pay the price” as it extended air traffic controls around Xiamen, the coastal city closest to the island.

Tensions have been escalating over Mrs Pelosi’s visit, which has yet to be officially confirmed but is almost certain to happen within the day.

Beijing views Mrs Pelosi’s planned visit as a provocation and has issued increasingly severe warnings that have not ruled out a military response.

“What I can tell you is, the US will definitely have to bear responsibility and pay the price for harming China’s sovereignty and security interests,” foreign ministry spokesman Hua Chunying told a regular press briefing in Beijing, adding that China will take “firm and powerful” measures in response.

“If the US misjudges or handles the situation across the Taiwan Strait incorrectly, it will have catastrophic consequences for the security, prosperity and order of the Taiwan region and the world at large.”

Mrs Pelosi has been on a tour of the Indo-Pacific which started in Singapore on Monday, followed by Malaysia.

A US air force jet that flew the delegation to Malaysia had left Kuala Lumpur on Tuesday afternoon, according to flight-tracking website Flightradar24 and Reuters witnesses. Reuters could not immediately establish if Mrs Pelosi or her delegation were on board.

While Taiwan does not feature on the official agenda, media reports have said she is widely expected to land in Taipei on Tuesday night.

Meanwhile, Xiamen Air said in an announcement on its website that some 30 flights have been affected by “(traffic) flow control”, without providing further details.

Most of the flights were heading from other Chinese cities to Xiamen, Fuzhou and Quanzhou in Fujian province. According to Flightradar24, the affected flights had paths crossing over the South China Sea, and have since been rerouted to take inland routes instead.

The Maritime Safety Administration also announced live firing exercises in parts of the Bohai Sea and South China Sea, barring vessels from entering both areas till midnight Saturday.

“Based on what I know, in response to Pelosi’s possible visit to Taiwan, Beijing has formulated a series of countermeasures, including military actions,” wrote nationalist commentator Hu Xijin on Twitter.

The retired editor-in-chief of the nationalist Global Times tabloid deleted a tweet over the weekend warning of military retaliation after Twitter blocked his account.

But the view that China should take military action is a popular one on Chinese social media, where eight of the top 10 trending topics on the Weibo microblogging platform were linked to Mrs Pelosi’s visit. Many netizens include references to the might of the People’s Liberation Army (PLA), which just marked its 95th anniversary on Monday.