The Middle East Quartet urged all parties in the region to work closely with its new envoy Tony Blair and said he would present proposals at a meeting in September.
In a statement after a meeting in Lisbon, the Quartet - the UN, the US, the EU and Russia - said it 'encouraged robust international support' for the former British prime minister.
UN head Ban Ki-moon, US Secretary of State Condoleezza Rice, Russian Foreign Minister Sergei Lavrov and EU foreign policy chief Javier Solana issued the joint statement.
It was their first meeting since the militant Islamist movement Hamas seized power in the Gaza Strip last month.
The Quartet welcomed US President George W Bush's 16 July statement renewing Washington's commitment to a negotiated two-state solution, and supported Bush's call for an international meeting in the autumn.
It also expressed support for the Palestinian Authority government headed by Salam Fayyad and welcomed the resumption of bilateral talks between Israeli Prime Minister Ehud Olmert and Palestinian president Mahmoud Abbas.
'The Quartet agreed to continue to consult regularly on developments, and to meet again in September to take stock of developments, hear from Mr Blair on his strategy for the economic and institutional agenda, and discuss the way ahead,' the statement concluded.
