The United States barred a prominent Palestinian activist from entering the country on Wednesday, a move that rights groups said was an attempt by the Trump administration to silence Palestinian voices.

The activist, Omar Barghouti, is one of the co-founders of the Boycott, Divestment, and Sanctions movement, also known as B.D.S., which encourages broad economic pressure on Israel over its treatment of Palestinians. The movement has increasingly come under fire in the United States, with some 27 states passing laws that punish companies or individuals who support the boycott.

Mr. Barghouti was supposed to speak at a series of events in the United States organized by the Arab American Institute in Washington, including at panels at Harvard University and an event with New York University. He was also planning to attend his daughter’s wedding in Texas.

“This U.S. entry ban against me, which is ideologically and politically motivated, is part of Israel’s escalating repression against Palestinian, Israeli and international human rights defenders in the B.D.S. movement,” Mr. Barghouti said in a statement. He called for an end to what he called “U.S. complicity in Israel’s crimes against our people.”