“He has a mild fever this afternoon and a slight sore throat. Although he was a bit tired, he was generally all right. His doctor had prescribed oral pills for him,” he said.

Hong Kong to push for stronger ties with Asia-Pacific countries: finance chief

The spokesman also said the chief executive, who received his fourth dose of the coronavirus vaccine in September, was undergoing home quarantine and could work remotely and attend video meetings if necessary.

On a citywide scale, health officials recorded 7,286 Covid-19 infections on Monday, 614 of which were imported, and 11 more deaths. Hong Kong’s current total tally stands at 2,043,967 cases and 10,610 related fatalities.

Meanwhile, the Executive Council, Lee’s de facto cabinet, would take a break from meeting on Tuesday, while the city leader would also refrain from a media briefing that day, the spokesman said.

Other officials would take Lee’s place at scheduled public events or other alternative arrangements to be made, the office said.

The Centre for Health Protection, meanwhile, listed Lee’s secretary, Priscilla To Kit-lai, and Carol Yip Man-kuen, the director of the Chief Executive’s Office, as close contacts required to undergo home quarantine.

Six other staffers who accompanied Lee during the trip were not classified as close contacts and will be allowed to return to their place of work.

Lee tested negative via rapid antigen screening conducted during his four-day visit to Bangkok, the spokesman said.

The chief executive arrived in Thailand on Thursday, with the summit starting on Friday and ending on Saturday.

The arrangements for the event had him seated next to Chinese President Xi Jinping during the closed-door sessions where they both took off their masks. However, no one-to-one meeting was arranged between the two.

He also sat next to Foreign Minister Wang Yi and met the Chinese ambassador to Thailand, Han Zhiqiang, twice during his trip.

A source familiar with state leaders’ movements said Lee’s infection “should not be a problem” for the officials as they had all been properly vaccinated.

“And we have prior experience of handling such situations during the top leader’s Hong Kong visit and earlier trip to central Asia,” the source said.

“The fact that China’s top leader has made the decision of joining the international meetings in person shows the country is very confident of ensuring the leaders’ health amid the pandemic.”

Professor David Hui Shu-cheong, a government pandemic adviser, said there was a risk Lee could have spread the virus to others if he had spoken to them without wearing a mask, despite the city leader having already received four vaccine doses.

“The first-generation vaccine could reduce the chance of developing severe symptoms and death but it could hardly prevent us from getting infected or infecting others because the new mutant strains can evade immunity,” he said.

However, Hui said the risk of Lee transmitting Covid-19 to others was “presumably” lower, given that he had repeatedly tested negative in Thailand, meaning his viral load at the time was not high.

Professor Lau Siu-kai, vice-president of the semi-official Chinese Association of Hong Kong and Macau Studies, said he believed the city leader’s infection was not a big deal because none of his travelling companions or President Xi had caught the virus from him.

The political scientists also said the incident was a reminder for Hongkongers to remain vigilant against the spread of the coronavirus.

“The Covid-19 pandemic is still ongoing and we should not let down our guard, especially when travelling overseas,” he said.

“John Lee himself should also set a good example and always wears a mask, except when joining those important meetings with other leaders.”

World leaders aware of Hong Kong’s return to global stage: city leader

Lee also met Thai Prime Minister Prayuth Chan-ocha and leaders such as Singaporean Prime Minister Lee Hsien Loong, Indonesian President Joko Widodo and Vietnamese President Nguyen Xuan Phuc. Prayuth later tested negative on Monday.

During a gala dinner on Friday, he was seated next to Widodo’s wife Iriana and Malaysian Chief Secretary Mohd Zuki bin Ali and was part of a leaders’ delegation to see Thai King Maha Vajiralongkorn.

The chief executive also hosted prominent local business leaders at a dinner on Saturday organised by the Hong Kong Trade Development Council. During the event, Lee was seated between Soopakij Chearavanont, a chairman of Charoen Pokphand (CP) Group, Thailand’s largest conglomerate, and the country’s deputy education minister Kalaya Sophonpanich.

On Sunday, Lee visited a Bangkok restaurant where he sampled the local cuisine and met staff from Hong Kong’s Economic and Trade Office in the Thai capital. He later went to grocery stores and other shops.

He also visited the offices of the CP Group and the Amata Corporation, a real estate company that specialises in industrial buildings. He met Dhanin Chearavanont, senior chairman of the CP Group and ranked Thailand’s richest man by business magazine Forbes.

Themed “Balanced, Inclusive and Sustainable Growth”, the regional forum featured more than 20 economies and was Lee’s first overseas trip since taking office as chief executive in July.

Lee was also joined by a 20-strong business delegation to Bangkok, which included Secretary for Commerce and Economic Development Algernon Yau Ying-wah and Hong Kong Trade Development Council Chairman Peter Lam Kin-ngok.

Headed by Yau, several delegation members remained in Thailand to meet Supattanapong Punmeechaow, the country’s deputy prime minister, and local business leaders before returning to Hong Kong later on Monday.

Hong Kong’s Cathay Pacific set to boost flights to Bangkok, Thai holiday spots

During the meeting, Punmeechaow acknowledged Thailand’s strong ties with China, adding that he looked forward to future collaborationsgarh

Yau said Hong Kong served as a bridge between mainland China and the West due to the “one country, two systems” governing principle, which was reaffirmed by President Xi during his trip to the city in July.

“The city also prides itself on its business-friendly environment, low and simple tax regime, free flow of information, capital, people and goods, and world-class infrastructure fully connected to global, regional and mainland Chinese markets,” he said.

Additional reporting by William Zheng and Emily Hung