The United States, Russia, European Union and United Nations made a joint call Tuesday on Israel and the Palestinians not to "undermine trust" as they embark on landmark peace talks.

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.

The group praised the "courageous decision" of Palestinian president Mahmud Abbas and Israel's Prime Minister Benjamin 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 Palestinians, 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.