In a statement released by the State Department Monday, Kerry lashed out against "partisan political" attacks against him, but acknowledged his comments last week to a closed international forum could have been misinterpreted. While he pointedly did not apologize for the remarks, he stressed he was, and is, a strong supporter of Israel, which he called a "vibrant democracy."
He said his remarks were only an expression of his firm belief that a two-state resolution is the only viable way to end the long-running conflict. And, he stressed, he does not believe Israel is, or is definitely track to become, an "apartheid state."
"I will not allow my commitment to Israel to be questioned by anyone, particularly for partisan, political purposes, so I want to be crystal clear about what I believe and what I don't believe," Kerry said after U.S. lawmakers and pro-Israel groups criticized him, with some demanding his resignation or at least an apology.
"First, Israel is a vibrant democracy and I do not believe, nor have I ever stated, publicly or privately, that Israel is an apartheid state or that it intends to become one," he said.
"Second, I have been around long enough to also know the power of words to create a misimpression, even when unintentional, and if I could rewind the tape, I would have chosen a different word to describe my firm belief that the only way in the long term to have a Jewish state and two nations and two peoples living side by side in peace and security is through a two-state solution," Kerry said.
On Sunday, The Daily Beast reported that Kerry had told a closed-door meeting of the Trilateral Commission in Washington on Friday that Israel risked becoming an "apartheid state" with two classes of citizens if negotiations to forge a peace deal fail and a two-state solution is not reached.
In his statement, Kerry defended his general point, noting that numerous Israeli officials, including Prime Minister Benjamin Netanyahu and predecessors Ehud Barak and Ehud Olmert, have offered similar assessments in the past.
But he said while Barak, Olmert and Israeli Justice Minister Tzipi Livni "have all invoked the specter of apartheid to underscore the dangers of a unitary state for the future, it is a word best left out of the debate here at home."
Netanyahu's office declined comment on Kerry's remarks. But Israeli Transportation Minister Yisrael Katz, a member of Netanyahu's Likud Party, wrote scathing criticism of the secretary of state on his Facebook page. Noting that Kerry's comments coincided with Israel's annual Holocaust memorial day, Katz wrote: "Shame on you, Kerry! There are words that mustn't be said."
Kerry's "apartheid" comment was also assailed by many in the pro-Israel community in the U.S.
House GOP leader Eric Cantor, R-Va., said Kerry should apologize, while the powerful American Israel Public Affairs Committee described his use of the term as "offensive."
Another pro-Israel lobby group demanded that Kerry resign, a call echoed by Republican Sen. Ted Cruz of Texas in a speech on the Senate floor.
Democratic Sen. Barbara Boxer of California was also critical of Kerry's comment, saying on Twitter, "Israel is the only democracy in the Middle East and any linkage between Israel and apartheid is nonsensical and ridiculous."
Kerry has invested significant time and energy into bringing Israelis and Palestinians to the negotiating table, with the goal of reaching a deal in nine months. That deadline expires Tuesday with the parties having failed to reach that settlement, a less ambitious framework deal or even an agreement to extend the negotiations. The State Department said Monday that U.S. envoy for Mideast peace Martin Indyk had come home from the region and had no immediate plans to return.
President Barack Obama, along with Kerry and other U.S. officials, has blamed the impasse on negative steps taken by both sides over the course of the last several months.
On the Israeli side, those include a decision not to release a group of Palestinian prisoners it had earlier agreed to free and announcements of new Jewish settlement construction on land claimed by the Palestinians. On the Palestinian side, they include a move to join numerous U.N. conventions they had agreed not to join while the negotiations were underway and, most recently, the announcement of a unity government with the radical Hamas movement, which Israel, the U.S. and Europe regard as a terrorist organization.
Associated Press writers Bradley Klapper in Washington and Josef Federman in Jerusalem contributed to this report.