The United States, Russia, European Union and United Nations - known as the Quartet - on Tuesday made a joint call on Israel and the Palestinian Authority not to "undermine trust" as they embark on peace talks, reported AFP.
The diplomatic Quartet on the Middle East said it was determined to support the two sides' "shared commitment to achieve a negotiated two-state solution within the agreed timeframe of nine months."
The Quartet "calls on all parties to take every possible step to promote conditions conducive to the success of the negotiating process and to refrain from actions that undermine trust," said a joint statement quoted by AFP.
The group praised the "courageous decision" of Palestinian Authority Chairman Mahmoud Abbas and Israel's Prime Minister Binyamin Netanyahu to launch the talks which started in Washington on Monday.
Envoys from the Quartet, which was set up to promote a road map toward peace between Israel and the PA, would meet "soon", the statement said.
"While noting that much hard work lies ahead, the Quartet expresses its hope that renewed negotiations will be substantive and continuous and set a clear path towards a two-state solution, the end of conflict, and lasting peace and security for both Israelis and Palestinians," said the statement, according to AFP.
Earlier Tuesday, U.S. Secretary of State John Kerry reaffirmed his government's commitment to a "two-state solution" between Israel and the PA, as he summed up the initial progress made between the sides.
Speaking at a brief news conference with Israeli negotiator Tzipi Livni and PA negotiator Saeb Erekat, Kerry noted was that "all final status issues... core issues and all other issues are all on the table."
Kerry also declared that the meetings - scheduled to restart some time in the next two weeks and continue over the course of nine months - will be held in complete secrecy.
U.S. President Barack Obama on Tuesday said that he was "hopeful" about the renewed talks. .
Obama, who travelled to Israel in March for his first visit to the region as president, met with Livni and Erekat. He has welcomed the start of new talks as a "promising step" forward, and promised U.S. support as the two sides mull the "hard choices" facing them.