President Donald Trump’s Gaza ceasefire plan is set to enter a new phase within weeks, but crucial pieces of the agreement remain undefined as Israel tightens its military grip on the battered enclave.

Israel's assassination of a senior Hamas commander threatens the viability of the Gaza ceasefire, the chief negotiator of the militant group said on Sunday, calling on U.S. President Donald Trump to demand Israel comply with the terms of the truce.

The founder of Russia's opposition Yabloko party, which wants a ceasefire in Ukraine, has said his party will keep campaigning despite the arrest of two senior figures, a move he said was meant to derail it before next year's parliamentary election.

Trump says the US is reviewing whether Israel broke the Gaza ceasefire with a strike that killed Hamas’s second-in-command Ra’ad Sa’ad, rejects reports of tension with Netanyahu.

The strike is the latest incident to strain the fragile ceasefire between Israel and Hamas brokered by US President Donald Trump, which took effect in October. The truce ended more than two years of fighting in the bloodiest war in the history of the Israeli-Palestinian conflict.

Analysts warn that Phase 2 of the ceasefire presents a host of complex challenges that could slow or even stall the process.

Archaeologists finished excavating foundations of the ancient wall that surrounded Jerusalem when the story of Hanukkah took place.

The message follows Israel’s killing of four Palestinians, including senior Hamas commander Raed Saad, over the weekend, despite the ceasefire.