UN Middle East envoy Nickolay Mladenov warned on Tuesday that Hamas-controlled Gaza on the verge of "full collapse", AFP reported.
According to Mladenov, a key to saving Gaza from disaster was restoring the government of Palestinian Authority (PA) chairman Mahmoud Abbas to power there, a decade after it was forced out by Hamas in a bloody coup.
"Without that Gaza risks exploding in our face again, this time in a far more deadly and violent manner than in the past," Mladenov was quoted as having said at the annual conference of Israel's Institute for National Security Studies in Tel Aviv.
Abbas's Fatah and Hamas signed a reconciliation deal last October, under which the PA was to have resumed full control of Gaza by December 1.
Sharp disagreements remain between the sides, particularly over the fate of public employees in Gaza and security control of the enclave.
Abbas has demanded that the armed militias in Gaza disarm as part of the implementation of the agreement, but Hamas has categorically rejected this demand.
"I often say publicly, in (UN) Security Council briefings and in other formats, that we are in the midst of a major humanitarian crisis," Mladenov said Tuesday, according to AFP.
"Let me be very clear today here, that we're well beyond that," he added.
"We're on the verge of a total systems failure in Gaza, with a full collapse of the economy, with social services, political, humanitarian and security implications stemming from that."