Israel said on Thursday it has begun preparations for the departure of large numbers of Palestinians from the Gaza Strip in line with President Donald Trump’s plan for the territory. Officials meanwhile said Egypt has launched an diplomatic blitz behind the scenes to try and head off the plan.

The Trump administration has already dialed back aspects of the proposal after it was widely rejected internationally, saying the relocation of Palestinians would be temporary. U.S. officials have provided few details about how or when the plan would be carried out.

The Palestinians have vehemently rejected Trump’s proposal, fearing that Israel would never allow refugees to return. Egypt has warned that an expulsion of Palestinians would destabilize the region and undermine its peace treaty with Israel, a cornerstone of stability and American influence for decades.