Israel will stop the entry of all humanitarian aid into Gaza to pressure Palestinian militant group Hamas into accepting a temporary extension of the ceasefire agreement, officials said on Sunday, a day after the initial phase of the truce expired.

Israel has introduced what it said was a new U.S. ceasefire plan and is trying to force Hamas to accept it by imposing a siege on the Gaza Strip.

Under the first, six-week phase of the ceasefire, Hamas released 25 Israeli hostages and the bodies of eight others in exchange for the release of nearly 2,000 Palestinians imprisoned by Israel. Israeli forces pulled back from most of Gaza and Israel allowed a surge of humanitarian aid to enter.