President Joe Biden’s recent executive order on international travel is raising concerns in Arizona border communities.

In that Jan. 21 order, Biden said that “to the extent feasible,” travelers entering the United States from abroad will need to show proof of a recent negative COVID-19 test before entering, as well as comply with CDC-recommended self-quarantines and isolation.

Federal agencies are also directed to reach out to Mexican and Canadian counterparts to develop protocols for land ports, and submit a plan within 14 days. That plan should “take into account the operational considerations relevant to the different populations who enter the United States by land.”

“I think the testing is where it’s going to get complicated,” said Joshua Rubin, vice president of business development for Javid LLC, which works with U.S. companies looking to open manufacturing facilities in Nogales, Sonora. He crosses almost every weekday.

He supports stronger border measures to slow coronavirus spread but said that strict testing requirements could be a significant challenge for the many border businesses with binational staff.

“Does that mean I come on Monday, spend the night here in Mexico, get tested and then on Friday I go home to be with my family, when I live literally 15 miles from my office?” he added.

Access to tests is also more limited in Sonora, where just over 106,000 tests have been done over the course of the pandemic. In contrast, more than 3.3 million diagnostic tests have been conducted in Arizona to date. In the lightest month last year, more than 130,000 people crossed through Nogales ports in personal vehicles alone, according to federal data.