NEW YORK: The US appears to be losing its appeal as a tourist destination, as a combination of political events and security concerns deter overseas visitors and threaten to hurt a $1.8 trillion industry.

Airfare analytics company Hopper noted a downturn in international web searches for round-trip flights to the US back in January around the time the newly inaugurated President Trump was instigating a ban on travellers from several Muslim-majority countries.

"We've almost never seen the negative impact of an event in the news cycle like this," Patrick Surry, chief data scientist at Hopper, told the Financial Times.

"Even when there's an event like a terrorist attack we normally see an uptick in searches because people are confirming, changing or cancelling their plans," he said.

Since the election in November, Hopper has seen a 49.5% drop in searches from China, the target of some of candidate Trump's ire.

That figure is likely to decline further in the wake of this week's United Airlines' debacle, which saw an Asian man, initially thought to be Chinese-American, forcibly removed from a plane.

The video of his removal has been seen by more than 600m viewers in China, according to the South China Morning Post, which also reported the response of the People's Daily.

The Communist Party mouthpiece described the airline as "arrogant and cold-blooded", adding: ""Who dares to fly with such an airline, which is supposed to uphold the values of taking care of people, but trampled over customers' rights and interests?"

The Trump administration's plans for "extreme vetting", which could see travellers from any destination required to hand over mobile phone contacts, social media passwords and financial data when entering the country, has added further to fears for the tourism sector.

The Center for Democracy & Technology has argued that demanding passwords or other account credentials without cause will not only fail to increase the security of US citizens, it "would discourage travel for business, tourism, and journalism".

A recent poll of European business travel professionals by the Global Business Travel Association found that almost half (44%) worked for organizations which had employees traveling abroad who might be or were affected by the US travel ban.

A similar proportion (45%) indicated their company would be less willing to plan future meetings and events in the United States.

Data sourced from Financial Times, IT Pro, South China Morning Post, GBTA; additional content by WARC staff