Donald Trump has said Hamas is gathering the Israeli hostages kidnapped and taken to Gaza more than two years ago before handing them over.
As part of a historic peace deal the 20 remaining living hostages will be taken back to Israel in exchange with 250 Palestinian prisoners.
It is expected the exchange will take place on Monday. Hamas said retrieving the bodies of the 26 hostages confirmed dead will take longer.
Meanwhile the fate of two is unknown.
Many of the Palestinian prisoners have been held without charge for the past two years, with many viewed as freedom fighters resisting decades of military occupation.
But Israel say they are terrorists with some of them involved in suicide bombings.