"Remember always that all of us ... are descended from immigrants and revolutionists," he said.
Cook was referring to a 1938 speech the President made during a gathering of the Daughters of the American Revolution, according to the American Presidency Project.
The Apple boss is one of Silicon Valley's more vocal opponents to President Donald Trump's policies on immigration, globalization, and climate change, and along with other tech CEOs, has been campaigning against the administration's travel ban on individuals from six Muslim-majority nations. Last week, the Supreme Court ruled to partially reinstate the ban while the court considers legal challenges in the fall.
Cook's tweet comes just weeks after he sat down with Trump and other tech chiefs in a roundtable discussion that included, among other issues, immigration. In the meeting, Cook told the President that he "needed to show more heart" on immigration issues, and that tech employees are "nervous" about the administration's approach, according to a New York Times reporter who was present.
After the first travel ban was announced in January, Cook wrote a memo to employees—some of whom had been directly affected by the executive order—saying that the company "believes deeply in the importance of immigration—both to our company and to our nation's future."
"It is not a policy we support," he continued.