As US House of Representatives Speaker Nancy Pelosi visited Taiwan vowing American commitment to defend the island, and Beijing condemned the highest-level US visit in 25 years as a threat to peace and stability in the Taiwan Strait, the Chinese ambassador to Nepal called the trip a serious violation of the one-China principle and the political foundation of China-US relations.

Issuing a statement on Wednesday, Hou Yanqi said: “[The visit] seriously infringes upon China's sovereignty and territorial integrity. It gravely undermines peace and stability across the Taiwan Strait. China firmly opposes and sternly condemns this, and has made serious démarche and strong protest to the United States.”

Pelosi arrived in Taipei late on Tuesday on a closely watched trip despite Beijing’s warnings.

Beijing expressed its anger with the presence of the US official on an island that it says is part of China with a flurry of military activities in surrounding waters, and by summoning the US ambassador in Beijing, and announcing suspension of several agricultural imports from Taiwan.

In Kathmandu, Hou said that since Speaker Pelosi is the incumbent leader of the US Congress, her visit to and activities in Taiwan, in whatever form and for whatever reason, is a major political provocation to upgrade US official exchanges with Taiwan.

“China absolutely does not accept this, and the Chinese people absolutely reject this,” Hou added. “There is but one China in the world, Taiwan is an inalienable part of China's territory.”

Earlier on Wednesday, Pelosi in her speech in Parliament in Taipei hailed the self-ruled island as “one of the freest societies” in the world.

Pelosi praised President Tsai Ing-wen, who Beijing suspects of pushing for formal independence—a red line for China.

“We thank you for your leadership. We want the world to recognize that,” Pelosi said, while also calling for increased inter-parliamentary cooperation, Reuters reported.

Hou in Kathmandu said in the statement that China will “definitely take all necessary measures to resolutely safeguard its sovereignty and territorial integrity in response to the US Speaker's visit.”

“All the consequences arising therefrom must be borne by the US side and the ‘Taiwan independence’ separatist forces. The Taiwan question is purely an internal affair of China. China strongly urges the United States to stop meddling in Taiwan and interfering in China's internal affairs,” said Hou. “It should stop supporting and conniving with ‘Taiwan independence’ separatist forces in any form. It must take credible actions to strictly observe the one-China principle and the provisions of the three China-US joint communiqués, and not go further down the wrong and dangerous path.”

Stating that China and Nepal are good neighbours, trustworthy friends and reliable partners linked by mountains and rivers, Hou said China highly appreciates Nepal’s longstanding commitment to the one-China principle resolutely opposing “Taiwan Independence.”

“It is also the political foundation of China-Nepal relations,” she said.

“The two countries have always understood and supported each other on issues of core interests concerning respective sovereignty, security and territorial integrity.”

“We believe that the government of Nepal and its people will continue to abide by the one-China principle and understand and support China’s legitimate and justified position and work together with China to defend each other’s sovereignty, security and territorial integrity,” she added.

Pelosi's visit to Taiwan follows heightened tensions and rhetoric between Washington and Beijing in recent years. Amid speculations that Pelosi could visit Taiwan, Chinese President Xi Jinping last week warned against “playing with fire” over Taiwan during a call with US President Joe Biden.

Beijing recently was at odds with Washington over Nepal matters as well, when it warned the US against “coercive diplomacy” over the Millennium Challenge Corporation compact.

Nepal has been adhering to one-China policy since the 1960s, however, Beijing constantly seeks reaffirmation from Kathmandu, and Hou’s latest statement comes along the similar line.