Wouter Geerts, a travel research consultant at Euromonitor, said Hong Kong was likely to stay in pole position, but added that its heavy reliance on the mainland China market was risky.

“I think Bangkok does not have anything that Hong Kong does not have, so I don’t think there will be any reason why Hong Kong should not remain No. 1 for a long time,” he said during the report’s in Hong Kong on Tuesday.

He said the special administrative region should develop its tourism market further, and not focus merely on shopping as its main attraction. Hong Kong has amazing outdoor experiences, and these being accessible via the MTR was just one of its offerings for tourists, he added.

“Asia continues its rise, accounting for 41 out of the top 100 cities globally in 2018, in comparison to 37 cities in 2012, with cities in Japan and India standing out for their strong growth in international arrivals,” said Geerts.

While overall mainland Chinese tourism is growing along with increased disposable incomes in the country, the researcher warned that a protracted US-China trade war could weaken travel, cutting into tourist-related revenue in cities like Hong Kong. The total loss of global travel revenue in such a case would be about US$1.8 billion, the group said. Thailand is among places that could lose the most – US$227 million – while Hong Kong and Japan could lose US$222 million and US$218 million, respectively, the researcher said.

Geerts said China would suffer significantly should there be an escalation of the trade dispute – which he estimates over three years could cut GDP by 1 per cent to 2 per cent in total – and this could impact mainland Chinese incomes and therefore how much is spent for travel.

“For China, the depreciation of the renminbi will actually result in an increase in demand from neighbouring countries, but a decline in outbound trips,” Geerts said.

Other mainland Chinese cities also figured in the top 100 of the rankings, with Guangzhou placing 18th; Shanghai, 26th; and Beijing, 54th.

If the trade war drags on, Geerts said, “we would expect to see a decline in the outbound growth from China of around 1.15 million trips in 2019, which would put the total outbound trips at around 107.1 million trips,” instead of the current projection of 108.3 million.

The preferred destinations of mainland Chinese tourists were a huge factor in determining how cities did on the list, the report said. This year, mainland Chinese took 97.5 million trips abroad, a figure that Euromonitor expects will more than double to 259 million in 2030.

“Hong Kong is the most obvious beneficiary of the Chinese outbound boom, with more than 50 per cent of all visitors stemming from the Chinese mainland,” the report said.

Infrastructure projects such as the Zhuhai-Macau-Hong Kong bridge, and the Guangzhou-Shenzhen-Hong Kong high speed rail link are expected to further boost the number of mainland Chinese visiting Hong Kong by cutting travel time in half to the city from major mainland cities.

Both of these projects started operating this year. An average 68,000 passengers have passed through Hong Kong’s port each day since the bridge opened on October 24. Meanwhile, the high-speed cross-border link saw an average daily patronage of 50,000.

Between January and October, 52.57 million tourists visited Hong Kong, of which 78.4 per cent or 41.29 million were from the mainland. That represented a growth of 13 per cent among Chinese visitors, versus a 0.9 per cent decline for visitors from elsewhere.

Mainland Chinese immigration authorities issued 133 million passports in 2017 and recorded more than 46 millions visits to Hong Kong and Macau by mainlanders, official data showed.

Other Asian cities that were among the 10 most visited cities in the world were Singapore (4th place); Macau, known for egg tarts and casinos (5th); Kuala Lumpur (9th); and Shenzhen (10th).

Popular cities in Asia that also figured in the top 20 were Tokyo (14th), where the 2020 Olympics will be held; and Taipei, popular for its vibrant street food offerings (17th).

Mainland Chinese tourists made their presence felt not only by boosting a destination to the top of rankings but also in pushing Seoul out of favour, following the South Korean government's decision to install a US-made anti-missile system in 2017. Seoul ranked 16th most visited city in 2017, but dropped to 24th this year, following Beijing's decision to boycott the South Korean tourism industry.

“After a huge decline in Chinese visitors due to political tensions, the number of foreign tourists visiting Seoul city shrank by 15 per cent to 7.7 million. However, arrivals are expected to pick up slightly in 2018, as political tensions with China ease, talks with North Korea progress and the 2018 Winter Olympics in Pyeongchang attract more visitors,” the report said.

Meanwhile, London ranked as the third most visited city and is Europe's top destination, followed by Paris at 6th. Dubai ranked 7th and was the only city in the Middle East and Africa in the top 10 list, while New York was the sole representative of the Americas, ranked 8th.

“Global inbound arrivals are expected to grow by 5 per cent to 1.4 billion trips in 2018. At the same time, arrivals to this year's top 100 city destinations are set to grow by 7. 5 per cent. This indicated that top cities are outperforming arrivals growth, with city hubs extending their importance for the global travel industry,” Geerts said.