NEW YORK – U.N. and Arab League Special Envoy for Syria Kofi Annan unexpectedly handed in his resignation today.

The Annan move came as the Syrian government and opposition forces intensified their fighting for control of Syria’s largest city, Aleppo.

At the same time, in an unprecedented move, the United Nations General Assembly, in a non-binding resolution, prepared to demand Syrian President Bashar al-Assad step down.

The vote is expected tomorrow.

The Annan resignation was announced as news came out of Washington that the White House had given the green light to U.S. intelligence agencies to increase their aid to Syrian rebel forces.

Annan, in a phone call to U.N. Secretary-General Ban Ki-moon, announced his decision to step down, claiming that the situation in Syria had deteriorated to the point that he doubted anyone could successfully mediate.

In a prepared statement, Ban explained: “It is with deep regret that I have to announce the resignation of the U.N.-Arab League Joint Special Envoy for Syria Mr. Kofi Annan.”

Ban added that Annan “deserves our profound admiration for the selfless way in which he has put his formidable skills and prestige to this most difficult and potentially thankless of assignments.”

In Geneva, Annan told reporters that recurrent “finger pointing” between the five permanent members — U.S., U.K., France vs. Russia and China — had all but neutralized his mediation.

According to U.N. sources, Annan first raised the possibility of resignation last week when he met Ban in London, where the U.N. chief was attending the Olympics.

The U.S. ambassador to the U.N., Susan Rice, insisted the Annan effort was doomed to fail.

“His mission could never had succeeded so long as the Assad regime continuously broke its pledges to implement the Six Point Peace Plan and persisted in using horrific violence against its own people,” she said.

Former U.N. Ambassador John Bolton said he was not surprised by the sudden turn of events.

“The U.N.’s entire diplomatic effort helped the Russians to try and buy time for Assad to crush the opposition. Both have failed,” he said.

Security Council President Gerard Araud of France says he was not surprised by the Annan decision and claimed that three earlier vetoes by the Russians and Chinese were directly responsible for the turn of events.

Israel’s U.N. mission declined comment. The U.S. mission also had no immediate reaction. Syria’s ambassador Bashar Jaafari was also silent.

In a recent Security Council meeting, Rice told members that the U.S. would not be deterred by Moscow and Beijing and would work “outside the council” to address matters in Syria.

Shortly thereafter, the U.S. led the move to terminate the mission of the U.N. observer force in Syria.

Then came the Annan resignation.

Both Ban and Araud insist the U.N. and Arab League peace plan is “still viable.”

But just who will lead the new effort and how was left unsaid.

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