Hamas is set to release six living Israeli hostages on Saturday and four bodies before then.
The head of the United Nations Office for Project Services (UNOPS), Jorge Moreira da Silva, made the appeal on a visit to Gaza on Thursday.
The Palestinian group recently said they could delay the release of hostages, after accusing Israel of breaching some of the terms of the ceasefire agreement.
A fragile ceasefire between Israel and Hamas in the Gaza Strip took hold in January.
Israeli authorities have seized any books relating to the Israeli-Palestinian conflict from the Educational Bookshop in East Jerusalem and detained its owners amid allegations they were “selling books containing incitement and support for terrorism.”
US President Donald Trump said he is committed to “buying and owning” Gaza and that other countries in the Middle East could help to rebuild it.
Israel says its forces have now withdrawn from a key Gaza corridor which means thousands of Gazans can now return home.
The Palestinians were released on Saturday afternoon in exchange for three Israeli civilian hostages whose gaunt appearances caused widespread condemnation.
As the US president announced controversial plans to “take over the Gaza Strip”, Euronews checked in with Arab American voters from across the political spectrum.
Residents in the strip talked to Euronews during a protest against the US president’s intentions in the central town of Deir al-Balah.