Poverty in the Gaza Strip has tripled this year under the Israeli blockade, according to the UN agency helping refugees living there.

John Ging, the head of the UN Relief and Works Agency (UNRWA) in Gaza, told reporters on Thursday that the number of Gazans considerered "abject poor" had tripled to 300,000 this year, equal to one in five Gazans.

Ging described the situation in the narrow and overcrowded Palestinian territory as "unbearable" and as a "man-made crisis", calling on Israel to ease its siege immediately.

"The humanitarian situation here in Gaza continues to deteriorate at an alarming rate for the ordinary poor citizens," Ging said.

He reported that 80,000 families, representing 400,000 Palestinian refugees, had applied to UNRWA for extra assistance.

"We now have three times more hardship cases. People cannot feed their families even with our assistance.

"At the start of this year, there were 100,000 people that were in our special hardship category, now we have another 200,000 added to that,

"Of course, sadly, this is the predictable consequence of the blockade and of the siege on Gaza. We want, once again, to call for the lifting of the siege on Gaza."

Gaza's economy has foundered under the blockade Israel imposed after the Hamas movement took control of the territory in 2007.

The UN provides food aid to nearly one million Gazans. It defines "abject poor" as those who cannot feed their families, even with UN assistance.

Ging said his agency urgently requires greater funding to fill the growing need.