WASHINGTON — Secretary of State John Kerry issued an unusual statement Monday evening expressing his support for Israel after a controversy erupted over a politically charged phrase he used in a private appearance.

Speaking to a closed-door meeting of the Trilateral Commission last week, Mr. Kerry said that if a Middle East peace agreement was not achieved, Israel risked becoming an “apartheid state,” according to an article in The Daily Beast, an online publication. The comments were noted in the Israeli news media and were severely criticized by some American Jewish organizations.

“Any suggestion that Israel is, or is at risk of becoming, an apartheid state is offensive and inappropriate,” the American Israel Public Affairs Committee said. “Israel is the lone stable democracy in the Middle East, protects the rights of minorities regardless of ethnicity or religion.”

Republican lawmakers were also critical. Senator Marco Rubio, a Florida Republican and possible presidential contender, said Mr. Kerry’s comments were “outrageous and disappointing.”