U.S. Secretary of State John Kerry returned to Israel on Thursday for talks the State Department says will include a proposed framework for the major issues standing in the way of an Israeli-Palestinian peace deal.
The latest trip comes amid stiffening resistance to his efforts to revitalize the Middle East peace process.
Positions on both sides appeared to have hardened recently over proposals regarding Jewish settlements and security arrangements in Palestinian parts of the West Bank that are under the control of Israeli security forces.
Israeli Prime Minister Benjamin Netanyahu told Kerry after his arrival that there is "growing doubt in Israel that the Palestinians are committed to peace."
There was no immediate comment from Palestinian officials.
Kerry, who will also meet with Palestinian President Mahmoud Abbas in Ramallah during the multi-day visit, said that while the U.S. commitment to Israel is "ironclad," a peace deal is not "mission impossible."
State Department spokeswoman Marie Harf said earlier this week that an agreement on the framework was not expected during this trip, but that there was a hope of "narrowing the gaps" that still separate the two sides.
Key issues that need to be resolved in a peace deal include borders, security questions, the fate of Jerusalem and the right of return for Palestinian refugees.
Israel and the Palestinians resumed the peace talks in July after a three-year break, and have committed to continue the negotiations through April.
Kerry has made a Middle East peace agreement a top foreign policy goal, and has made frequent trips to the region in the past year.