According to travel search site Kayak (PCLN.O), searches from Europe for flights to the U.S. are down by 12 percent since the elections.
Demand for travel to the United States over the coming months has flattened out following a positive start to the year, with uncertainty over a possible new travel order likely deterring visitors, travel analysis company ForwardKeys said on Monday.
ForwardKeys, which analyses 16 million flight reservations a day from major global reservation systems, also said that travel from the United States to and from the Middle East has been especially hard hit after President Donald Trump's move to ban people from seven Muslim-majority countries.
"Uncertainty reigns and the presidential rhetoric appears to be deterring visitors to the U.S.," ForwardKeys founder Olivier Jager said in a statement.
U.S. travel demand is set to be a topic at the world's largest travel fair, the ITB, in Berlin this week.
After the travel ban was imposed in January, international travel to the U.S. dropped by 6.5 percent in the following eight days, ForwardKeys data showed last month.
In its latest update on Monday, ForwardKeys said bookings to the United States recovered after the courts halted the ban, but dropped again in the nine days after plans for a new ban were announced on Feb. 17.
Overall, bookings for travel to the United States over the next three months are 0.4 percent down on last year, whereas they had been 3.4 percent ahead the day before the travel restrictions were imposed.
The study also showed that accumulated U.S. bookings to the Middle East were up by 12 percent on last year in the three weeks before the ban. However, in the four weeks following the ban they were down 27 percent.
Emirates and Qatar Airways, two of the Middle East's biggest airlines, declined to comment when asked about demand on U.S. routes.
(Reporting by Victoria Bryan; additional reporting by Alexander Cornwell in Dubai; editing by Alexander Smith)