Facebook CEO Mark Zuckerberg spoke out today against the immigration policies of President Donald Trump.

“We are a nation of immigrants, and we all benefit when the best and brightest from around the world can live, work and contribute here,” Zuckerberg said in a Facebook post.

In his first days in office, President Trump signed executive orders to restrict visas and deny entry to refugees from specific Muslim-majority countries. He also signed an order to extend a border wall (multiple walls already exist on the U.S.-Mexico border in places like San Diego). Trump has suggested that the wall will be built with a 20 percent import tax on goods made in Mexico and brought to the United States. As a result, Mexico’s President Enrique Peña Nieto canceled a trip to Washington that was scheduled to take place next week.

“We need to keep this country safe, but we should do that by focusing on people who actually pose a threat. Expanding the focus of law enforcement beyond people who are real threats would make all Americans less safe by diverting resources, while millions of undocumented folks who don’t pose a threat will live in fear of deportation,” Zuckerberg said in a Facebook post Friday.

Trump has also threatened to revoke federal funding from sanctuary cities — cities that say they will not turn over undocumented immigrants to Immigrations and Customs Enforcement (ICE) officials. Sanctuary cities argue that threats of deportation quiet undocumented people who may otherwise speak with law enforcement, which can lead to more crime.

Zuckerberg said he supports Trump’s decision to “work something out” for the young undocumented people who are allowed to live and work in the United States under the Deferred Action for Childhood Arrivals (DACA) program.

In the post, Zuckerberg also said Facebook will work more closely with Fwd.us in the coming weeks “to find ways we can help.” Fwd.us is an immigration tech group whose members include Zuckerberg, Bill Gates, and Yahoo CEO Marissa Meyer. Throughout the Obama administration, Fwd.us advocated for increases in H-1B visas that bring engineers and tech talent from other countries to the United States.

With the exception of executives at Facebook, tech companies have been relatively quiet about actions taken by the new president in his first week in office.

But on Thursday, Facebook COO Sheryl Sandberg criticized the policy direction of the Trump administration when she said the White House’s new abortion policy “could have terrible consequences for women and families around the world.”