Israeli Prime Minister Benjamin Netanyahu said Mahmoud Abbas should have condemned Hamas' "war crimes" instead of Israel in his speech at the United Nations General Assembly in New York.
The Israeli leader held up a picture from France 24 of three children playing near a Hamas rocket launcher before condemning the militant Islamist group.
"You see three children playing next to them. Hamas deliberately put its rockets in areas like this. Ladies and gentlemen, this is a war crime," he said.
"I say to Abbas, these are the war crimes committed by your partners in the unity government that you are responsible for. These are the war crimes that you should have investigated and spoken out against in your speech last week."
Netanyahu attacked militant Islam throughout his speech in Iran, Nigeria and Gaza, comparing Hamas to Isis (now known as the Islamic State) and Boko Haram.
"The people of Israel pray for peace, but our hopes and the world's hopes for peace are in danger because everywhere we look militant Islam is on the march," he said.
"All politics is local. For the militant Islamists, all politics is global because their goal is to dominate the world.
"Last week, many of the countries represented here, rightly applauded [US President Barack] Obama for fighting Isis. Yet weeks before, these very countries opposed Israel for confronting Hamas.
"They evidently don't understand that Isis and Hamas are branches of the same poisonous tree."
A sharp speech was expected in response to Palestinian Authority President Mahmoud Abbas' critical UN address last week.
The Palestinian leader stated Israel was committing "genocide" against the Palestinian people.
"In the name of Palestine, I affirm here today, we will not forget or forgive, or allow war criminals to escape unpunished," he said.
"Israel has chosen to make it a year of a new war of genocide perpetrated against the Palestinian people."
In the recent seven-week conflict between Israel and the militant faction Hamas, over 2,100 Palestinians - mostly civilians - lost their lives. All but five of the 68 Israeli fatalities were soldiers.