A new outlook on U.S. business travel included something unusual as of late — unexpected good news. But it came with a giant asterisk.

The Global Business Travel Association said Thursday that its latest quarterly forecast on business travel volume and spending in the U.S. was a slight upgrade from the previous one, which anticipated volume growth of 2.7 percent and 3.8 percent spending growth in 2017.

Instead, the outlook calls for volume to increase 2.9 percent this year, to more than 537 million business trips originating in the U.S. Spending is expected to increase 4.4 percent to $296 billion. That’s a departure from 2016, when volume increased only slightly and spending decreased.

In 2018, volume is expected to reach almost 554 million trips and spending is forecast to grow another 5.2 percent to nearly $312 billion.

“Slightly more optimism around the growth in foreign markets along with renewed domestic growth expectations following Trump’s surprising presidential victory have helped to support better expectations for business travel performance in 2017 and 2018,” the report says.

But the forecast, produced by Rockport Analytics, was completed before President Donald Trump signed a controversial executive order late last month barring travelers from seven Muslim-majority countries.

While the ban has been put on hold by a federal judge — a decision upheld by an appeals court — surveys have shown that companies are already planning to cut back on business travel as a result. About $185 million in business travel bookings were lost in the week that came after the ban, GBTA said.

A revised order is expected as early as next week, and the association is warning that the growth it expected to see this year and next could be threatened by a new ban. GBTA released the outlook Thursday along with a long cautionary note from executive director and chief operating officer Michael McCormick.

“Completed after the election, but before President Trump took office, the forecast…is now very much in jeopardy,” he wrote. “This will be especially true if we continue to see losses like we witnessed in the week following the travel ban.”

McCormick wrote that the travel ban could have a long-term negative impact if it causes countries beyond the seven named in the order — Iran, Iraq, Libya, Somalia, Sudan, Syria, and Yemen — to reconsider holding meetings and events in the U.S.

“Closing our borders sends a message to the world that the United States is closed for business,” he wrote.

Photo Credit: Travelers move through a security line at Hartsfield-Jackson Atlanta International Airport. The Global Business Travel Association says the forecast for business travel growth has improved. David Goldman / Associated Press