The Middle East peace "Quartet" has called on the Israelis and Palestinians to work closely together ahead of Israel's planned withdrawal from Gaza.
Israel's military is getting ready for the planned pull-out from Gaza
The statement came after a meeting in London of foreign ministers from the four powers working for peace in the Middle East, the US, UN, EU and Russia.
They called it a "moment of optimism" that could boost the peace process.
Earlier in the week, a meeting between the leaders of the two sides ended in disappointment for the Palestinians.
It was overshadowed by the detention of at least 50 Islamic activists in the West Bank after a weekend of attacks on Israelis.
The Quartet said contacts between the Israelis and Palestinians "should now be intensified at all levels".
With less than two months to go before the planned withdrawal from Gaza and parts of the West Bank, there is an "urgent need for Israel and the Palestinians to work directly and cooperatively with each other."
They called on Israelis to take "immediate steps" to ease the hardships facing Palestinians in the occupied territories and allow them more freedom of movement.
On the Palestinian side, there needs to be judicial and legal reform, greater transparency on the part of the Palestinian Authority and anti-corruption measures, they said.
"Rapid reform of the security services and strengthening of the rule of law are essential elements that can improve security for Palestinians and Israelis alike," the Quartet said in its statement.
The four ministers also underlined the need for donors to support US envoy James Wolfensohn's efforts to improve the living standards of the Palestinians.
The Quartet's chief aim is to ensure Israel's planned withdrawal is not an end in itself but serves to bolster the wider peace process, says the BBC's diplomatic correspondent Jonathan Marcus.