Hovering over this month's annual gathering of world leaders at the United Nations is the international community's failure to end the escalating war in Syria that is starting to spill over into a fragile and divided region.

The Syrian conflict has bitterly divided the most powerful members of the Security Council, paralyzing the only U.N. body that can impose global sanctions and authorize military action.

It frustrated former U.N. secretary-general Kofi Annan, who quit his high-profile role as special envoy to the country last month, giving reasons that amounted to scathing criticism of world powers for failing to unite to stop the chaos in the Arab state.

There will be a flurry of meetings on the sidelines of the VIP gathering at the General Assembly that begins Sept. 25, including a ministerial meeting of the Security Council's five veto-wielding members and lots of behind-the-scenes discussions among the more than 130 heads of state and government coming to New York. But frustrated diplomats don't expect any breakthrough on Syria, and outside observers agree.

This "means we're heading into a very dark time in Syria -- more violence and a slow grinding conflict that's going to test everyone's limits on non-intervention," Andrew Tabler, a senior fellow and Syria expert at the Washington Institute for Near East Policy, told The Associated Press in an interview Monday.

"I think it's the elephant in the room in the sense that it's a lightning rod issue," Tabler said. "It's a crisis the U.N. is unable to deal with. And so, basically what happens is that you're going to have a lot of speeches ... but unless you get the Security Council agreeing I don't see anything happening."

Since the Syrian conflict began in March 2011, the division among the five powerful permanent council nations has deepened.

The United States, Britain and France have tried unsuccessfully to get the council to put pressure on President Bashar Assad's government to halt the fighting and pull back its heavy weapons.

Russia, Syria's key protector, and China, which is supporting Moscow, are demanding equal pressure on the opposition and say the West's real goal is regime change, which could lead to a takeover of Syria by Islamist radicals. Russia is the major arms supplier to Syria and has a base in Tartus. It is its only naval base outside the former Soviet Union that serves Russian navy ships on missions to the Mediterranean.

Russia and China have vetoed three Western-backed resolutions, the latest in July which included the threat of non-military sanctions.

France's U.N. Ambassador Gerard Araud said Monday that the Security Council "has never been as paralyzed as it is today since the end of the Cold War."

France is now working with the U.S., Britain, Turkey, Arab friends and the Syrian opposition in its fight against the Assad regime, he said.

"It is essential that we support the democratic opposition in Syria," Araud said. "Some believe it is possible to choose between Assad and the Islamists. We tell them, `If you keep blocking, you'll get Assad and then the Islamists."'

U.S. Ambassador Susan Rice said the council's failure to support efforts by U.N. Secretary-General Ban Ki-moon and Annan to end the violence is "reprehensible and has only intensified the suffering of the Syrian people. "

"I am not optimistic in the short term that the dynamic in the council is going to change," she said. "However, the United States is not allowing that to block our efforts to speed the day when Assad departs, through sanctions and political and nonlethal support for the opposition."

President Barack Obama has called for Assad to step down, but the United States wants to ensure that whatever government replaces his regime is a democracy that respects the rights of all Syrians, particularly religious minorities and women.

Annan has been replaced with former Algerian foreign minister Lakhdar Brahimi, a highly regarded diplomat and mediator who met Assad in Damascus on Saturday, but gave no indication of a breakthrough.

Many countries are hopeful that Brahimi can get the government and opposition to peace talks, but he has called his mission "nearly impossible."

He has said he is still holding talks with key players and does not have a plan yet.

"I will go to New York for the occasion of the General Assembly, to meet the Security Council and foreign ministers and representatives of countries that have interest, influence or both concerning Syria," Brahimi said.

The Security Council has given its support to Brahimi, but its division is so deep now that members couldn't even agree on a statement last month on the humanitarian crisis. The conflict has left some 3 million Syrians inside and outside the country in need of food and other assistance.

Michael Weiss, research director at the London-based Henry Jackson Society think tank, said no breakthrough is likely at the General Assembly because Russian President Vladimir Putin has done nothing "to repudiate Assad." Also, he added, Obama is reluctant to intervene in the Middle East as he fights for reelection on a record of ending the U.S. military role in Iraq and setting a 2014 deadline to withdraw from Afghanistan.

"All you are going to see for the next six months or longer is this continuing state of civil war," Weiss said. "The rebels may assassinate members of the Assad regime, but until they have parity of weaponry and forces, Damascus will not fall."

The West has hesitated to arm the rebels for fear that costly and lethal equipment could fall into the hands of extremists like al-Qaida, or get lost. The rebels have received weapons delivered via Turkey, Iraq and elsewhere, according to activists and diplomats. Some of the arms, activists say, are purchased with Saudi and Qatari funds.

The Syrian conflict, which began as a protest against four decades of dictatorship by the Assad family, was spawned by the Arab Spring, the pro-democracy wave of uprisings across the Middle East that began when Tunisians rose up in January 2011 against their longtime dictator.

The changes in the Arab world since then are the theme of a ministerial-level meeting of the Security Council on Sept. 26 on the sidelines of the General Assembly speeches.

Germany U.N. Ambassador Peter Wittig, the current Security Council president whose foreign minister will be presiding at that meeting, said "there will be council members who will speak out on Syria." But he said the focus of the meeting will be the emergence of the Arab League as a key player in the Middle East with "a lot more clout."

Supporters of a democratic government in Syria -- the "Friends of Syria" -- are also scheduled to meet on Sept. 28 at a session chaired by Secretary of State Hillary Rodham Clinton. Their last meeting in Paris in July brought together some 100 nations including the U.S., its European and Arab partners, as well as the fractious Syrian opposition, all looking to turn up the heat to force Assad from power.

Britain's U.N. Ambassador Mark Lyall Grant said "Syria will be at or near the top of the agenda at most of the key bilateral meetings."

There will also be a meeting of foreign ministers and development ministers "to galvanize support for refugees and those displaced within Syria," he said.

Earlier this month, the United Nations nearly doubled its humanitarian appeal for Syria to $347 million, even though the original appeal for $180 million is only half-funded. The secretary-general has urged donors to increase their contributions.

Another issue certain to make headlines during the General Assembly is the dispute over Iran's nuclear intentions.

Iran's President Mahmoud Ahmadinejad, who insists his country's nuclear program is peaceful, will address the assembly on Sept. 26. Israel's Prime Minister Benjamin Netanyahu, who has accused Iran of trying to build a nuclear arsenal, takes the podium on Sept. 27.

And on that day political directors from the six countries trying to get Iran to suspend its nuclear enrichment program -- the U.S., Russia, China, Britain, France and Germany -- will meet behind closed doors, possibly followed by a ministerial session.