Palestinian Authority President Mahmoud Abbas has been accused of “diplomatic terrorism” after he claimed Israel carried out a "war of genocide" in Gaza during his speech at the UN General Assembly.

Mr Abbas called for what he described as Israeli "war crimes" in Gaza to be punished, but stopped short of saying he would pursue charges against Israel. He has previously threatened to take Israel to the International Criminal Court.

"This last war against Gaza was a series of absolute war crimes carried out before the eyes and ears of the entire world, moment by moment," Mr Abbas said. The devastation unleashed, he asserted, "is unmatched in modern times."

The conflict between Gaza and Israel in July and August devastated some districts and killed more than 2,100 Palestinians, most of them civilians, according to the Gaza health ministry.

Sixty-seven Israeli soldiers and six civilians in Israel were also killed. Israel began the offensive on 8 July with the stated aim of halting cross-border rocket salvoes by Hamas and other militant groups.

The devastating war is believed to have weakened Abbas domestically, with his Hamas rivals enjoying a surge of popularity among Palestinians for fighting Israel.

In pictures: Israel-Gaza conflict - summer 2014 Show all 18 1 /18 In pictures: Israel-Gaza conflict - summer 2014 In pictures: Israel-Gaza conflict - summer 2014 Israel-Gaza conflict A Palestinian woman uses a piece of reebar she found amid the rubble, for support as she walks past destroyed homes in a street in Beit Hanun, northern Gaza Getty Images In pictures: Israel-Gaza conflict - summer 2014 Israel-Gaza conflict Palestinian men wait for their names to be called to receive a ration of food aid at a UN compound in Gaza City Getty Images In pictures: Israel-Gaza conflict - summer 2014 Israel-Gaza conflict Posters calling people to boycott Israeli products Getty Images In pictures: Israel-Gaza conflict - summer 2014 Israel-Gaza conflict Residents of a neighborhood in Gaza City gather to put out a fire at a soap factory moments after it was hit by an Israeli airstrike In pictures: Israel-Gaza conflict - summer 2014 Israel-Gaza conflict A Palestinian, who was injured in clashes in the Gaza strip, is carried on a stretcher to an ambulance after the arrival of a group of injured Palestinians at Ankara's Esenboga airport In pictures: Israel-Gaza conflict - summer 2014 Israel-Gaza conflict A Palestinian, who was injured in clashes in the Gaza strip, is carried on a stretcher to an ambulance after the arrival of a group of injured Palestinians at Ankara's Esenboga airport In pictures: Israel-Gaza conflict - summer 2014 Israel-Gaza conflict Firefighters try to extinguish a fire that witnesses say was caused by an Israeli air strike in Gaza City. Israel has accepted a new Gaza ceasefire proposed by Egyptian mediators and will send negotiators to Cairo if the truce holds, Israeli officials said In pictures: Israel-Gaza conflict - summer 2014 Israel-Gaza conflict Smoke from fires caused by Israeli strikes rises over Gaza City In pictures: Israel-Gaza conflict - summer 2014 Israel-Gaza conflict People watch as a fire burns in a building that witnesses say was hit by an Israeli air strike in Gaza City In pictures: Israel-Gaza conflict - summer 2014 Israel-Gaza conflict Palestinian fire fighters extinguish a blaze at a soap factory moments after it was hit by an Israeli airstrike In pictures: Israel-Gaza conflict - summer 2014 Israel-Gaza conflict Palestinian firefighters try to put out the fire at a cleaning materials factory after it was hit by Israeli airstrike in Al-Meena neghbourhood in the west of Gaza City In pictures: Israel-Gaza conflict - summer 2014 Israel-Gaza conflict Palestinians react as they put out a fire in an apartment which witnesses said was hit by an Israeli air strike in Beit Lahiya in the northern Gaza Strip In pictures: Israel-Gaza conflict - summer 2014 Israel-Gaza conflict A relative kisses the body of Palestinian Nader Driss, whom medics said died of a gunshot wound by Israeli troops during clashes at a protest against the Israeli offensive in Gaza, during his funeral in the West Bank City of Hebron In pictures: Israel-Gaza conflict - summer 2014 Israel-Gaza conflict Relatives of Palestinian woman Amani Baraka, whom medics said was killed in an Israeli air strike, mourn during her funeral in Khan Younis in the southern Gaza Strip In pictures: Israel-Gaza conflict - summer 2014 Israel-Gaza conflict A Palestinian boy, whom medics said was wounded by Israeli shelling, is visited by members of a local aid society wearing costumes at a hospital in Gaza City In pictures: Israel-Gaza conflict - summer 2014 Israel-Gaza conflict Jamal Doghmosh, a 48-year-old Palestinian mechanic who was injured in an Israeli air strike, recuperates at Shifa hospital in Gaza City. When Doghmosh woke up in hospital after the attack, he could not hear properly and found that three fingers from his right hand were also gone. He is one of thousands of Palestinians who have been left physically disabled by the conflict with Israel in the Gaza Strip In pictures: Israel-Gaza conflict - summer 2014 Israel-Gaza conflict An injured Palestinian man from the Al-Elaa family sits inside his house after it was hit by an Israeli military strike in the Jabalia refugee camp, in the northern Gaza Strip In pictures: Israel-Gaza conflict - summer 2014 Israel-Gaza conflict A view of the living room of the Okasha family house destroyed by an Israeli strike, in Jebaliya refugee camp, Gaza Strip. Two female members of the family were critically wounded in the strike

"We will not forget and we will not forgive, and we will not allow war criminals to escape punishment," Mr Abbas said in his 30-minute address.

His remarks were angrily condemned by the United States as “provocative” and “counterproductive”.

"President Abbas' speech today included offensive characterizations that were deeply disappointing and which we reject," State Department spokeswoman Jen Psaki was quoted by the Associated Press as saying.

Israel denounced the allegations as "a speech of incitement filled with lies." The Israeli Foreign Minister Avigdor Lieberman said his comments "highlight once again how he does not want and cannot be a partner for a reasonable diplomatic agreement” and accused Mr Abbas of "diplomatic terrorism".