U.S. hoteliers are seeing a decline in European travelers' U.S. hotel bookings as of late, and the drawback is causing hoteliers across the country concern.

While it’s hard to say what’s causing the drop, economic uncertainty across Europe coupled with many Europeans’ dislike of President Donald Trump is exacerbating the problem, Hotel News Now reports. Hotel management firm PM Hotel Group started analyzing reservations originating from other countries after the presidential election and found declines  in visits to NYC and San Francisco, but also found an uptick in U.S. transient reservations.

While the two roughly cancel each other out, experts fear the drop in European travelers will hurt more in the months where they account for a larger share of occupancy rates. Foreign guests account for less than 5% of NYC’s occupancy in the winter, but in the summer months that number usually climbs to 20%. [HNN]