Hopes of a "two-state solution" in the Israeli-Palestinian conflict are in "serious danger", French Foreign Minister Jean-Marc Ayrault has warned.
"We must act, urgently," he said at a French-led conference in Paris aimed at reviving the stalled peace process.
Officials from the Middle East Quartet, the UN, Arab League and more than 20 states attended the discussions.
The Palestinians described the talks as "a very significant step", while Israel criticised the meeting.
Neither side was represented at the Paris gathering.
Mr Ayrault said urgent actions were needed "to preserve the two-state solution, revive it before it is too late".
Major powers were aiming to work out this month a number of security guarantees and economic incentives to encourage Israel and the Palestinians to resurrect the peace talks by the end of 2016, he added.
French President, Francois Hollande, also warned that the threats posed by regional wars in the Middle East made a settlement between Israel and the Palestinians even more urgent.
The consensus among diplomats appeared to be that any effort to revive the peace process was better than nothing at all, correspondents said, even though few were optimistic about concrete results.
The initiative was praised by Palestinian officials but criticised by Israel, saying the meeting "only hardened Palestinian positions and pushed peace further away".
Israeli Foreign Ministry spokesman Emmanuel Nahshon, quoted by AFP, also said "the international community accepted [Palestinian leader] Mahmoud Abbas's demand and enabled him to continue to evade direct and bilateral negotiations without preconditions".
Discussions about discussions: By Jeremy Bowen, BBC Middle East editor
France's President Francois Hollande issued a warning about doing nothing. Violence he said was rife, and hope diminishing.
The final communiqué said the status quo was not sustainable. Continuing violence was alarming and so was the expansion of Jewish settlements on land the Palestinians want for a state. Both Israelis and Palestinians would have to show, through policies and actions, that they were committed to a two state solution.
The Palestinians welcome the internationalisation of attempts to end the conflict. They believe they get more sympathy from European countries than from the United States.
The Israeli foreign ministry called the conference a missed opportunity. It said pressure should have put on Mr Abbas, to talk one on one with Israel's Prime Minister, Binyamin Netanyahu.
That suggests the Israeli government feels under pressure. Mr Netanyahu has also been criticised for appointing a controversial hardliner, Avigdor Lieberman, as defence minister. Former Prime Minister Ehud Barak said the move showed the seeds of fascism had infected Israel.
Meanwhile, senior Palestinian negotiator Saeb Erekat told the BBC that "the mere fact that they met in Paris, these 26 countries along with the EU, the Arab League and the UN is a very significant step."
"And I think President Hollande really pinpointed the issue here: if we continue our failure in the peace process, if this Israeli government continues its policies of settlement and dictations and fait accompli policies, the day after will be the day for the extremists."
There have been numerous rounds of peace talks between Israel and the Palestinians since the early 1990s, with the most recent collapsing in acrimony in April 2014.
The Palestinians accused Israel of reneging on a deal to free prisoners, while Israel said it would not continue negotiations after the Palestinians decided to bring the Islamist Hamas movement into a unity government.
French diplomatic sources - quoted by AFP - said Friday's discussions would focus on the 2002 Saudi peace initiative, which offered Arab recognition of Israel in return for the creation of a Palestinian state in territories occupied by Israel since 1967.
On Monday, Israeli Prime Minister, Benjamin Netanyahu, said the Saudi plan included "positive elements". He has called for "direct negotiations without preconditions between the sides".
However, the managing director of Israel's foreign ministry, Dore Gold, likened the French talks to the 1916 Sykes-Picot agreement, which carved up the Middle East between colonial powers.
US Secretary of State, John Kerry attended the Paris talks. But Reuters news agency quoted a US official as saying Washington did not have any new proposals to put forward.
Some of the most intractable issues include the status of Jerusalem, Jewish settlements in the occupied West Bank and Palestinian statehood.