The Palestinian Islamist group Hamas on Monday accused Israeli Prime Minister Benjamin Netanyahu of obstructing negotiations for a truce and hostage release in Gaza as mediators again push for a deal.

The devastating war in the Palestinian territory is nine months old but back-and-forth negotiations, which have lasted nearly as long, have failed to end it.

In a statement, Hamas said the Israeli prime minister "continues to place more obstacles in front of the negotiations".

The movement accused Netanyahu of escalating "his aggression and crimes against our people" in what it said were "attempts to forcibly displace them in order to thwart all efforts to reach an agreement".

As heavy battles raged in Gaza City on Monday, the Israeli military expanded its evacuation order in the territory's north, leaving thousands of Palestinians on the move.

Netanyahu's office reiterated in a statement on Sunday that "any deal will allow Israel to return and fight until all the goals of the war are achieved".

With the exception of a one-week truce in November, which saw 80 Israeli hostages freed in exchange for 240 Palestinians held in Israeli prisons, talks have repeatedly foundered over differences between the parties.

Mediators Egypt and Qatar were due to host new meetings this week, according to officials.

An official with knowledge of the mediation said US Central Intelligence Agency (CIA) director William Burns would also go to Qatar this week.

Hamas has signalled it would drop its insistence on a "complete" ceasefire, a demand Israel has repeatedly rejected.

In its statement on Monday the militant group said it had shown "flexibility and positivity to facilitate reaching an agreement" and urged mediators to end what it called "Netanyahu's tricks and crimes".