TAOYUAN, Taiwan - Taiwanese Vice-President William Lai returned on Friday from a sensitive visit to the United States, a trip China has condemned and which has brought warnings from Taiwanese officials that it could prompt more Chinese military drills near the island.

“Because of everyone’s hard work, Taiwan’s power is stronger and stronger, and it showed the international community that Taiwan is a force for good, that the international community really pays great attention to Taiwan,” he said after returning to Taiwan’s main international airport in Taoyuan.

China claims Taiwan as its territory and denounced the transit stops in the US, calling Mr Lai a separatist and a “troublemaker”.

Taiwanese officials have said that China is likely to conduct military exercises this week near the island, using Mr Lai’s US stopovers as a pretext to intimidate voters ahead of 2024’s presidential election and make them “fear war”.

Democratically governed Taiwan has so far not reported any unusual Chinese military movements near the island.

Amid heightened tensions between China and the US, there has been a flurry of military posturing and drills from both sides in recent weeks.

On Thursday, Japan’s government reported 11 Chinese and Russian naval ships, including destroyers, had crossed the waters between the southern Japanese islands of Okinawa and Miyako, a waterway crucial to access to the Pacific and East China seas.

The islands lie directly to the east of Taiwan and Okinawa is home to a major US military base.

A person familiar with security planning in the region said the China-Russian fleet had conducted simulation attacks on US forces stationed in Okinawa, as well as drills to seize strategic locations.

The USS Ronald Reagan carrier strike group was also in the waters about 1,500km off Taiwan’s eastern coast as at Thursday evening, the person added.

The US Navy’s Carrier Strike Group 5, whose flagship is the USS Ronald Reagan, said the strike group “continues to perform routine operations in the Philippine Sea”, but did not elaborate.

A spokesman for Japan’s Joint Staff Office said it was not aware of any such simulations by the Chinese and Russian fleets.

“They have not intruded into Japan’s territorial waters and we have not confirmed any dangerous behaviour,” the spokesman said.

“We have offered through diplomatic channels that the repeated joint actions of Chinese and Russian forces in the sea and airspace around Japan are a serious concern from a security perspective,” he added.

Russia’s Defence Ministry said Russian and Chinese ships “conducted anti-submarine drills, repelled an air raid by a mock enemy, trained for rescue operations at sea, and mastered skills for take-offs and landings on decks of war ships”.

China’s Taiwan Affairs Office and Defence Ministry did not immediately respond to requests for comment.

Stopover diplomacy

On Friday, the Taiwan Defence Ministry’s official news agency put out a slickly produced publicity video which showed fighter jets taking off and missiles being readied.

“Nobody can encroach on our sovereignty,” reads an accompanying caption for the video titled “The military of the Republic of China is duty-bound to maintain regional peace and stability”, referring to Taiwan’s formal name.

Mr Lai officially made only transits in the US – first in New York and then in San Francisco – on his way to and from Paraguay to attend the new President’s inauguration in one of only 13 countries that maintain formal ties with Taipei.

While in the US, he gave speeches to the Taiwanese community and met officials from the American Institute in Taiwan, a US government-run non-profit that handles unofficial relations.

Mr Lai is the front runner to be Taiwan’s next president at elections set for next January. President Tsai Ing-wen cannot run again after two terms.

Mr Lai has previously made comments about being a “practical worker for Taiwan independence” though he has pledged on the campaign trail to maintain the status quo and offered talks with Beijing.

Speaking after his flight, he made only passing mention of his US stopovers, concentrating instead on Paraguay and pledges of support he received there.

“Thank you for your contributions to the country and to society, allowing Taiwan to very progressively, self-confidently and respectfully go into the international community, and winning the support of the international community,” he said. REUTERS