More than 100 European Union parliament members say they object to a unilateral declaration of Palestinian statehood in September.
In a letter addressed to EU Foreign Policy Chief Catherine Ashton, parliamentarians from several states and from across the political spectrum assert that one-sided Palestinian moves will push peace further away.
The signatories say that they are "all united in the conviction that only a negotiated two-state solution can end the Israeli-Palestinian conflict."
"Past agreements between the parties and international mediators clearly reject unilateral actions," the letter notes, urging the sides to resume negotiations immediately and stressing that "both sides will have to make difficult compromises to reach an agreement."
Only an immediate return to negotiations - for which pressure must be exerted on all parties - can save the peace process," the letter reads.
However, the Obama administration's efforts to re-launch stalled Israeli-Palestinian peace talks this summer are going nowhere, and a looming UN confrontation could further set back prospects for a negotiated settlement any time soon.
Senior officials from the international group of Mideast peacemakers - the US, the UN, the European Union and Russia - planned to meet Monday in Washington. The goal is to revive the process by increasing pressure on the two sides to return to talks.
Obama administration pessimistic? (Photo: Pete Souza)
The mediators "will come together and will compare notes about where we are and plot a course forward," State Department spokeswoman Victoria Nuland said Friday.
Yet one US official privately described the overall atmosphere surrounding the Israeli-Palestinian peace process as gloomy. A second termed it depressing. The officials spoke on condition of anonymity to discuss confidential meetings.
The deadlock had split the United States and its allies about how to restart the talks. Until last week, the US had resisted European calls for the meeting Monday, believing there was nothing new to discuss, officials said.
The US concluded that it wasn't worth continuing to fight the meeting despite the poor prospects for success, officials said.
AP contributed to the story