US Secretary of State John Kerry insisted Wednesday the only way to secure a lasting peace between Israel and Palestinians is to negotiate a two-state solution to their conflict.

Explaining the US decision last week not to veto a UN Security Council vote to condemn Israeli settlement building, Kerry said: "The vote in the UN was about preserving the two-state solution.

"That's what we were standing up for: Israel's future as a Jewish and democratic state, living side by side in peace and security with its neighbors," he said.

"The two-state solution is the only way to achieve a just and lasting peace between Israelis and Palestinians," Kerry said, but warned that solution was in "serious jeopardy."