Syndicated columnist Charles Krauthammer sharply rebuked Secretary of State John Kerry Monday on Special Report for his remarks about Israel potentially becoming an "apartheid state" if the Israeli-Palestinian conflict was not resolved.

To compare Israel's treatment of Arabs with the systemic racism of apartheid in South Africa, Krauthammer said, was "truly appalling and hurtful" and agreed with Sen. Ted Cruz (R., Texas) that Kerry should offer his resignation.

"it's beyond nonsense," he said. "It's pernicious and extremely harmful. What the Secretary of State of the United States has succeeded in doing in what he thought was a private comment is to echo and therefore to legitimize the worst of the libelous (claims) against the Jewish state. If there is one minority in the Middle East that enjoys the rule of law and protection and democracy, it is Arabs in Israel … This is beyond something requiring an apology. I think this is a resigning-type statement. This is an injury to an ally that will echo, because it will be repeated. People will say, ‘I'm not saying this, it is the Secretary of State of the United States.' It's untrue, it's pernicious and it's truly something that demands at the very least an immediate apology."

Lawmakers on both sides of the aisle condemned Kerry's remarks. Sen. Barbara Boxer (D., Calif.) tweeted any linkage between Israel and apartheid was "nonsensical and ridiculous."

Fellow Fox News analyst Juan Williams implied that Kerry's comment carried less weight because it was made in private, but Krauthammer retorted it was now public and that Kerry had "legitimized" and "encouraged" a hateful term often used by Palestinians opposing Israel.