Israel is intensifying military operations in one of the last Hamas strongholds in Gaza, as the sides stake out positions before ceasefire negotiations proposed by US President Donald Trump.

Hamas is seeking guarantees that a new U.S. ceasefire proposal for Gaza would lead to the war's end, a source close to the militant group said on Thursday, as medics said Israeli strikes across the territory had killed scores more people.

Israel has agreed to a U.S. proposal for a temporary ceasefire with Hamas after reneging on a previous path for peace earlier this year, Israeli Foreign Minister Gideon Saar reportedly confirmed Wednesday.