Israel swore in a new commander of its military as a standoff over the fragile ceasefire in Gaza increased the risk of a resumption of fighting without an agreement to bring home the rest of the hostages still held by Hamas.

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.

Hundreds of aid trucks have entered Gaza daily since the ceasefire began on Jan. 19​, and it was unclear what the immediate impact of the aid cutoff would be.

Foreign Minister Gideon Saar said on Tuesday Israel was ready to proceed to the second phase of the Gaza ceasefire deal, as long as Hamas was ready to release more of the 59 hostages it is still holding.

UN Secretary General António Guterres, who has arrived in Cairo for Tuesday's emergency Arab summit on rebuilding Gaza, called for the "immediate" resumption of assistance. He urged "all parties to make every effort to prevent a return to hostilities".

A tense cease-fire between Israel and Hamas continued to hold amid a stalemate over an Israeli block on humanitarian aid going into Gaza after Hamas rejected a U.S. proposed extension.

Israel is giving Hamas “several days” to rethink terms for a new Gaza ceasefire, raising the prospect of further pressure tactics or a resumption of war.