The US secretary of state has warned Israel on the danger of a possible collapse of the Palestinian Authority, saying its demise would threaten the security of the Jewish state.
John Kerry said calls from some Israeli politicians to let Palestinian President Mahmoud Abbas' administration wither are counterproductive and self-defeating for Israel.
If it were to happen, Kerry said, Israel would be forced to assume all governance in the occupied West Bank.
Kerry also said without a two-state solution, Israel would be forced into an unsustainable position of perpetual occupation that would be rejected by Palestinians and the international community.
"If there is a risk that the PA [Palestinian Authority] could collapse - and it is in Israel's interest for it to in fact survive, as the prime minister suggested - should more therefore not be done to help sustain it?" said Kerry, speaking at the Brookings Institution in Washington DC on Saturday. 
"The one-state solution is no solution at all for a secure, Jewish, democratic Israel living in peace. It is simply not a viable option."
 Israeli-Palestinian violence continues as Kerry meets Netanyahu
He called on Israeli Prime Minister Benjamin Netanyahu to stick to his commitment to the two-state solution and engage in dialogue with the Palestinians.
"It is important that that not become a slogan, not become a throw-away phrase, that it becomes a policy, which is what it is meant to be," he said.
Netanyahu insisted on Sunday his country was not heading towards becoming a "binational state".
"But in order to have peace, the other side needs to decide that it wants peace as well," Netanyahu said.
Kerry also criticised Israel's continued expansion of Jewish settlements in areas that the Palestinians claim as part of a future state, noting Palestinians were prevented from construction activity in Area C of the occupied West Bank.
The remarks by the top US envoy came a week after he met Palestinian and Israeli leaders in Ramallah and Jerusalem.
Kerry noted during the recent trip that Abbas had told him the level of Palestinian despair about the future was unprecedented.
He "spoke more despairingly, my friends, than I have ever heard him, about the sense of hopelessness that the Palestinian people feel", Kerry said.
At the same time, Kerry told the conference the Palestinian leadership must do more to prevent anti-Israel violence.
Deadly attacks have rocked the occupied Palestinian territories and Israel for more than two months following Israeli incursions into the al-Aqsa Mosque compound.
Since October 1, 112 Palestinians have been killed along with 21 Israelis, an American, and an Eritrean.