WASHINGTON — The United States banned entry to Israeli Knesset member Michael Ben Ari, reportedly because of his membership in Kach, a banned terrorist group.

Ben Ari, a member of the right-wing National Union, had been seeking to visit the United States to attend two conferences.

Israeli media quoted Ben Ari as saying last week that the ban stemmed from his association with Kach, the anti-Arab group founded in the 1970s by the late Meir Kahane.

The State Department has listed Kach and other Kahane-founded groups as terrorist organizations. Reuven Rivlin, the Knesset speaker, wrote to Daniel Shapiro, the U.S. ambassador, protesting the decision.

“As an elected public representative in the State of Israel, a close friend of the United States, he should neither be considered a member of any terrorist organization nor should be prevented from visiting the United States,” Rivlin said.

A State Department spokesman would not comment on the matter, citing privacy considerations.