Trump signed an executive order to review high-skilled H-1B immigration visas

(Update: Trump signed his executive order targeting the H-1B program on Tuesday afternoon.)

U.S. President Donald Trump will order a full review of the country’s high-skilled immigration visa program tomorrow, part of a continued push to clamp down on companies — including, potentially, some in the tech industry — that hire foreigners instead of Americans.

In a forthcoming executive order, Trump will commission the Department of Homeland Security, which issues the popular H-1B visa, to review the way they are rewarded. The agency is also instructed to suggest reforms so that visas only land in the hands of highly paid, specially skilled applicants, and not foreign workers who might be paid less than their U.S. counterparts.

On its face, Trump’s new directive — a push to “buy American, hire American,” as his aides described it today — does not change the immediate day-to-day working of the H-1B system, which many companies in Silicon Valley support. Instead, at least for the moment, it only opens a formal review of the program. The president plans to tout the initiative during a visit to Wisconsin tomorrow.

Still, Trump’s move may leave many in the tech industry wary, as it’s the latest in a line of restrictions and changes the administration has introduced to the high-skilled foreign worker visa in recent weeks.

Earlier this month, the Trump administration promised greater scrutiny of H-1B visas — including “site visits” to determine whether “H-1B dependent employers are evading their obligation to make a good faith effort to recruit U.S. workers.” With it, officials at DHS also said they would require programmers applying for H-1B visas to prove they’re doing specialized, complex jobs. Experts saw both moves as attempts to crack down on Indian outsourcing companies, like Infosys and Tata Consultancy Services.

The Justice Department, meanwhile, issued a stern warning to companies in April, stressing it would “not tolerate employers misusing the H-1B visa process to discriminate against U.S. workers.” The DOJ also signaled in a federal court case this month that the Trump administration may target a related program that allows the spouses of some H-1B holders to seek employment. Before becoming the agency’s leader, Attorney General Jeff Sessions had been a vocal critic of tech giants like Facebook that sought to hire more foreign workers.

Early word of Trump’s plans to rethink the H-1B visa program first surfaced in January, as the president issued the first version of another immigration executive order, which targeted travelers and refugees from seven majority-Muslim countries.

After months of quiet, however, tech executives, including Apple CEO Tim Cook and Amazon CEO Jeff Bezos, received an early warning about Trump’s coming directive on a call last week with Jared Kushner, the president’s top adviser and son-in-law. Kushner convened them and other executives as part of his tech-focused efforts with the White House’s new Office of American Innovation, according to two sources familiar with the matter.

This article originally appeared on Recode.net.