Some European companies are increasingly wary of sending their employees to the United States

This is due to the turbulent policies of the Trump administration, stricter immigration inspections and increased reporting on detention and deportation.

Some companies, CNBC, talked in areas including engineering and accounting, highlighting their ongoing work to the United States. However, others often tag attention to employee welfare in more politically sensitive areas.

Their responses range from posting new travel guides (such as suggesting workers bring wipe electronics or entering the United States through Canada) to encouraging participation at possible online events or online meetings.

Business travel is an important source of income for the U.S. economy. The industry's total spending generated a total of $421 billion and $119 billion in tax revenue in 2022, according to a report published last year by the Global Business Travel Association (GBTA), which is the complete data available in the past year. This comes from an estimated 429 million business trips supporting 6 million jobs.

Business travel is also a key revenue manufacturer in the aviation industry, with airlines accounting for 50% to 75% of profits in many cases.

In April GBTA's 900 global travel buyers survey, 29% said they expect corporate business travel to fall in 2025 due to U.S. travel and tariff policies. The survey also found that overall optimism in the industry has declined.

Any chilling effect of international tourism is expected to undermine the cost of $12.5 billion this year due to negative perceptions of trade and immigration policies.

Since Donald Trump took office in January, border controls and foreign visas have been under high charge, with reports of tourists being held in detention centers for a long time. The White House promised in January that all foreigners seeking to enter the United States would be “under censorship and screening, with the highest degree.”

The relationship between the U.S. government and academia has also become sore after suspending the issuance of international student visas and "actively revoked" visas for Chinese students, and detaining some foreign students on obvious political reasons.

"We have heard some international travelers express uneasiness about censorship of visits to the United States, social media surveillance and detention or deportation despite valid documents," said Prashray Kala, a partner at Management Consultancy Group, a management consulting firm.

"Those with visible online footprints are more cautious, especially when the 'Catch and Revoke' policy enhances surveillance," Kara said.

The policy was announced on April 30, meaning that no matter how serious it is, anyone who violates U.S. law loses their immigration status after a strike.

A European fund manager who frequently travels to the U.S. to conduct business said he was concerned that immigration authorities at the airport could hinder his travel plans due to changes in political attitudes rather than policies.

"Business travel (Visa) on ESTA is no longer a thing of the past," the fund manager said.

Responsible for an international non-governmental organization

This policy goes beyond their usual requirements for information about employees’ movement and contact information, i.e., issues surrounding physical and information security. NGOs have submitted investigation reports on topics involving climate change, corporate malfeasance and corruption.

Employee CNBC talked about the story, asking to discuss internal workplace issues anonymously.

"On one level, as an organization, this shouldn't really require us to sweat, and we do that for many places where our employees travel," said the NGO CEO.

"But from a personal point of view it's a very illuminating - not a very pleasant way - because these are all kinds of things that come to mind when I go to China or Azerbaijan's authoritarian regime. The idea that we have to apply this approach to the United States is that I wouldn't have happened until a few months ago."

Examples, they said, include adopting a “burner” phone or computer that is only used for travel, and preparing employees for positive doubts about their intentions to travel or what they post online.

Additionally, an academic researcher at a Swiss university told CNBC that they have provided guidance to travel through Canada where possible, or actually attend a conference to avoid any visa complications.

They noted that some of their colleagues are still traveling to the United States without any incidents, but some are questioned at the border for longer periods of time and some decide not to attend summer academic conferences. They added that the visits to American universities have been particularly affected and even put on hold.

All of these CNBCs have talked to in various industries, and the general climate around our travels is one of the uncertainties.

"Of course, there is the risk of overreacting … more time and resources to prepare for it than actual, tangible risk warrants," said the head of the NGO.

"There is always a question of how you distinguish the brute frenzy from what might be substantial. I think this time this time, and we're going to take more clumsiness seriously."

- Ganesh Rao of CNBC contributed to this story.