The Zambia women’s national team have removed their four U.S.-based players from the squad for the Yongchuan International Tournament in China due to concerns over U.S. travel measures, the Zambia FA said on Wednesday.

FAZ general secretary Reuben Kamanga said Orlando Pride trio Barbra Banda, Prisca Chilufya and Grace Chanda, along with Bay FC forward Racheal Kundananji would not be available owing to additional travel measures introduced by the new administration in the United States.

The Zambia FA did not say what “travel measures” it was referring to. But the Trump administration’s crackdown on illegal immigration, stepped up checks of foreign student visa holders and a potential ban on travel from some countries has made many foreigners who live in the U.S. question whether they should travel abroad lest they have difficulty re-entering the country.

In an executive order signed in January, Trump told his Cabinet members to submit a report within 60 days that identifies countries with vetting so poor that it would “warrant a partial or full suspension” of travelers from those countries to the U.S.

U.S. State Department spokeswoman Tammy Bruce said last month that the review was ongoing and no list had been finalized. It’s unclear whether China will be on the list.

The four NWSL players will stay back in the United States, Kamanga confirmed.

“After working through the process instigated by recently introduced measures it was decided that it is in the best interest of our players to skip this assignment,” Kamanga said in a statement.

“They will definitely be available for future assignments as they were for the last window when we played Malawi.”

An NWSL spokesperson said in a statement: “As a global league, we recognize the unique pressures facing international athletes in the current geopolitical climate. We are committed to ongoing collaboration with FIFA and other governing bodies, as well as our clubs, the NWSLPA, and the federal government, to advocate for long-term solutions that protect their ability to compete on both the domestic and international stage.”

A Bay FC spokesperson said: “We don’t have any statements or new information, but we can confirm that Racheal did not travel.”

Meanwhile, Portland Thorns forward Deyna Castellanos will not travel home to Venezuela for matches on April 5 and 8 against Panama. Her agent confirmed that a “lack of clarity on the travel bans” was the reason.

Zambia begin their tournament against Thailand on Saturday.

Information from Reuters, The Associated Press and ESPN’s Jeff Kassouf contributed to this report.