U.S. Republican Presidential nominee Mitt Romney attacked President Barack Obama's Middle East policy late Sunday, stepping up the pressure after a wave of anti-U.S. protests in the Islamic world.

In an op-ed piece in The Wall Street Journal, Romney said of recent "disturbing" developments in the Middle East that the United States "seems to be at the mercy of events rather than shaping them.

International sanctions could trigger a popular uprising in Iran similar to last year's revolution in Egypt that toppled President Hosni Mubarak, Israel's foreign minister said in statements published Sunday.

"The opposition demonstrations that took place in Iran in June 2009 will come back in even greater force," Foreign Minister Avigdor Lieberman said in an interview published by Israel's Haaretz newspaper.

Israel has already breached its own red line set by Prime Minister Benjamin Netanyahu by acquiring "dozens of nuclear warheads," Iranian Defense Minister Ahmed Vahidi said on Saturday.

"If having the atomic bomb is passing the red line, the Zionist regime, that possesses dozens of nuclear warheads and weapons of mass destruction, has passed the red line years ago, and it has to be stopped," he said, according to the ISNA news agency.

Israel's threats of military action against Iran over its nuclear programme only serve to boost the defiance of the Islamic republic, the head of the Revolutionary Guards said on Friday.

"The enemies want to stop us continuing our path... but these threats only reinforce our determination to continue in the same direction," General Mohammed Ali Jafari said in a speech to thousands of members of the country's Basij militia, according to the Guards' Sepahnews website.

Israel's media on Friday splashed their front pages with pictures of Prime Minister Benjamin Netanyahu literally drawing a red line for Iran on a bomb diagram at the United Nations General Assembly.

But while some commentators took jabs at the cartoonish visual aid, they said Netanyahu had scored a major PR coup, winning global headlines while setting a deadline that could help ease tense relations with the White House.

Israeli Prime Minister Benjamin Netanyahu drew the world a stark red line Thursday, warning that Iran could have a nuclear bomb in less than a year and demanding international action.

Wielding a red marker pen and a cartoonish diagram of a round bomb with a fizzing fuse, Netanyahu told the U.N. General Assembly that the international community must put a limit on Tehran's uranium enrichment.

Israeli Prime Minister Benjamin Netanyahu was to set a "clear red line" on Iran's controversial nuclear program in a speech to the U.N. General Assembly later Thursday, an Israeli official said.

"In his speech, the prime minister will set a clear red line" on Iranian nuclear activities, a senior Israeli official told reporters traveling with Netanyahu as his plane arrived in New York.

The leaders of Israel and the Palestinian Authority both address the United Nations on Thursday, one seeking recognition for his state, the other warning of a dire threat to his.

One year after Mahmud Abbas made his historic appeal to the U.N. General Assembly for Palestinian statehood, he returned with the more modest goal of seeing his territory given a kind of elevated non-member observer status.

Israeli Defense Minister Ehud Barak believes Israel should evacuate dozens of isolated Jewish settlements in the West Bank while annexing larger blocs that are home to most of the settler population.

In excerpts of an interview in Yisrael Hayom published Monday, Barak said he was mulling a plan which would see Israel relinquish dozens of settlements while allowing residents of big blocs -- Gush Etzion, Maale Adumim and Ariel, where up to 90 percent of the settlers live -- to become part of Israel.

Israel is trying to thaw the frosty relationship between Prime Minister Benjamin Netanyahu and the White House, and set up a meeting with President Barack Obama, an Israeli newspaper said on Friday.

A report in the Maariv daily said National Security Adviser Yaakov Amidror was in Washington and had been "meeting senior White House officials for the past two days in an attempt to reach certain understandings regarding the red lines that must be set for the Iranian nuclear program."