Kerry, in a major speech on the frozen Middle East peace process, said "equivalent swaps" of land could happen to modify the border, but only by mutual consent.
Jerusalem, he argued, should be recognised as the capital of both states and those countries that do not recognize Israel as a Jewish state should do so.
"It is up to Israelis and Palestinians to make the difficult choices for peace but we can all help," he said, laying out the United States recommendations for reviving the peace effort.