Tech companies on Saturday expressed concerns over President Donald Trump's order to restrict migration from several countries, with leaders saying the move could directly impact their own staffers.

Silicon Valley's chieftans provided emotional support, as well as offers of legal assistance to employees affected by an executive order that banned all non-citizens from seven predominantly Muslim countries from entering the United States for at least 90 days.

The ban, which came only weeks after Trump sat down with Silicon Valley's top executives to express support for their innovation efforts, extends to workers who have visas and green cards and are currently out of the country.

A federal judge granted an emergency stay Saturday to temporarily allow people with valid visas who landed in the U.S. to stay in the country. The American Civil Liberties Union estimates it will affect between 100 and 200 people detained at or in transit to U.S. airports. It will not, however, stay the president's entire order.

In an internal memo obtained by CNBC, Apple (AAPL) CEO Tim Cook told employees, "There are employees at Apple who are directly affected by yesterday's immigration order. Our HR, Legal and Security teams are in contact with them, and Apple will do everything we can to support them."

Cook concluded by quoting Dr. Martin Luther King: "We may have all come on different ships, but we are in the same boat now."

Executives from Microsoft (MSFT), Google (GOOGL), Netflix (NFLX), and Y Combinator, as well as educators at MIT and Carnegie Mellon, were among technology leaders who condemned President Donald Trump's wide-reaching order. The decision effectively blocks travelers from Syria, Iran, Iraq, Libya, Somalia, Sudan and Yemen.

Brad Smith, Microsoft's president and chief legal officer wrote on LinkedIn that there are 76 Microsoft employees from the 7 countries who have work visas, and are affected by the new order. It is offering those employees legal support regarding immigration.

"We share the concerns about the impact of the executive order on our employees from the listed countries, all of whom have been in the United States lawfully, and we're actively working with them to provide legal advice and assistance," Microsoft told CNBC.

Facebook (FB) also told CNBC that it was assessing how to protect its workers from adverse effects.

Facebook CEO Mark Zuckerberg was one of the first to address the ban publicly. "We need to keep this country safe, but we should do that by focusing on people who actually pose a threat," Zuckerberg wrote on Facebook on Friday.