The Gazainfo-icon Strip may already be "unlivable", a U.N. official warned Tuesday, after a crippling Israeli blockade.

Robert Piper, the U.N.'s top humanitarian official in the Palestinian territories, told AFP in an interviewinfo-icon to mark a new report on living conditions in Gaza all the "indicators are going in the wrong direction".

"We predicted some years ago that Gaza would fast become unlivable on a host of indicators and that deadline is actually approaching even faster than we predicted - from healthinfo-icon access, to energy to water," he said.

A 2012 U.N. report predicted the Palestinian enclave would be "unlivable" by 2020 if nothing was done to ease the blockade.

Piper pointed out that power supplies were down to as little as two hours a day in Gaza, where medical care had been slashed and youth unemployment was over 60 percent.

In such circumstances "for most of usinfo-icon that unlivability point has already been passed," he said.

"And yet somehow the Gazans soldier on."

The Palestinian movement Hamas was elected to govern Gaza in 2007, leading Israelinfo-icon to impose a crippling blockade which critics say punishes all of the two million residents indiscriminately.

Since 2013 Egyptinfo-icon, the only other country with which Gaza shares a border, has largely closed off its crossing and destroyed hundreds of smuggling tunnels that provided a vital lifeline for the economyinfo-icon.

The new U.N. report, "Gaza - Ten Years Later," says more than 95 percent of Gaza's water is now unfit for drinking, while electricity supplies have reached critical levels in recent months - falling to only a few hours a day