More than 400 European parliamentarians have urged leaders to use Joe Biden's new presidency as an opportunity to stop what they term Israel's "de-facto annexation" of the occupied West Bank.
A letter seen by AFP was signed by 400 European politicians from across a range of backgrounds who serve in national legislatures and senates or in the European parliament.
Addressed to European foreign ministers and EU foreign policy chief Josep Borrell, the letter argues that "the Biden administration presents a chance to correct course" in Middle East diplomacy.
"The previous US administration left the conflict farther away from peace than ever," it added.
Former president Donald Trump broke with much of the international consensus concerning the Israeli-Palestinian conflict.
Trump recognised Jerusalem as Israel's "undivided capital" and moved Washington's embassy there, infuriating the Palestinians who claim the eastern part of the city as the capital of their future state.
The State Department under Trump also said it no longer viewed Jewish settlements in the occupied West Bank as illegal.
Trump's widely criticised Middle East peace plan ear-marked parts of the West Bank for Israeli annexation.
Possibility of peace
While the Trump plan is dead, settlement expansion continues, with Israel regularly approving the construction of new homes for Jews on occupied Palestinian territory.
Israeli Prime Minister Benjamin Netanyahu, a close Trump ally, agreed to pause West Bank annexation plans in exchange for the diplomatic normalisation with the United Arab Emirates.
"However, developments on the ground clearly point to a reality of rapidly progressing de facto annexation, especially through accelerated settlement expansion and demolitions of Palestinian structures," said the letter.
"Europe must work with the Biden administration, countries in the region and the parties on the ground to prevent unilateral action undermining the possibility of peace, advance the rights and security of all people under Israel's effective control."
Israel's occupation of the West Bank began following the 1967 Six Day War, the conflict that also saw it seize control of east Jerusalem, an area it later annexed.
The European Union insists any viable Israeli-Palestinian peace deal must be based on Israel's pre-1967 borders -- a condition rejected across much of the Israeli political spectrum.
Biden has indicated his administration will restore US opposition to West Bank settlements expansion, but he does not intend to move the US embassy back to Tel Aviv.
The letter also said that Gaza, the Israeli-blockaded Mediterranean enclave, "remains at risk of violent escalation at any moment", blaming both the blockade and "intra-Palestinian divisions".
Hamas Islamists who have controlled Gaza since 2007 are long-standing rivals of Fatah secularists who dominate the Palestinian Authority, but the two sides are engaged in a unity push ahead of Palestinian elections called for later this year.
"Palestinian reconciliation and elections across all the Palestinian territory is vital, including as a basis for ending the isolation of Gaza," the letter said.