Egypt's new president on Wednesday hit out at Israel over its veiled threats to attack Iran's nuclear facilities and the deadlock in the Middle East peace process.

President Mohamed Morsi received a rousing ovation for his first speech to the 193-member UN General Assembly since becoming Egypt's first civilian, democratically elected leader in June.

Without specifically mentioning Israel's undeclared nuclear arsenal, Morsi said the Middle East "no longer tolerates" any country's refusal to join the nuclear Non-Proliferation Treaty "especially if this is coupled with irresponsible policies or arbitrary threats."

"The acceptance by the international community of the principle of pre-emptiveness or the attempt to legitimize it is in itself a serious matter and must be firmly confronted to avoid the prevalence of the law of the jungle," Morsi said.

The election of the Islamist politician has unsettled ties with Israel, which has refused to rule out a military strike on Iran's nuclear facilities.

Morsi also put the Israel-Palestinian conflict ahead of the Syria war in the list of priorities he laid out before the General Assembly.

"The first issue which the world must exert all its efforts in resolving, on

the basis of justice and dignity, is the Palestinian cause," Morsi said.

He said that UN resolutions on the conflict had not been implemented and that Palestinians "must also taste the fruits of freedom and dignity" that other countries in the Arab region have won in the past year.

"It is shameful that the free world accepts, regardless of the justifications provided, that a member of the international community continues to deny the rights of a nation that has been longing for decades for independence," Morsi said.

"It is also disgraceful that settlement activities continue on the territories of these people."

The Palestinians have refused to hold direct talks with Israel for the past two years because of Israel's refusal to halt settlement activities in the occupied territories.

Israel's Prime Minister Benjamin Netanyahu and Palestinian leader Mahmud Abbas are to address the General Assembly on Thursday.