the US election, Obama will seek to reassure American voters as well as world leaders that they can count on him to handle the latest global challenges, even as Republican challenger Mitt Romney seizes the chance to pan his foreign policy.
Obama will talk tough with nuclear-defiant Iran, take Syrian President Bashar al-Assad to task for efforts to crush an 18-month uprising and reflect on a recent eruption of violent anti-American protests in Muslim countries, aides say.
But he is not expected to offer any new solutions to problems that have cast a cloud over this week's high-level gathering at the U.N. General Assembly and now threaten to chip away at a foreign policy record his aides hoped would be immune to Republican attack.
With campaign pressures building in a close race, Obama's final turn on the world stage before facing voters has left little doubt about his immediate priorities.
He skipped the customary one-on-one meetings with foreign counterparts but went ahead with the taping of a campaign-style appearance on the popular television talk show "The View" - a tradeoff that drew Republican criticism.
United Nations Secretary-General Ban Ki-moon speaks at the 67th UN general Assembly at UN headquarters. AP Photo/John Minchillo
Obama planned to be in and out of New York in 24 hours, one of the briefest presidential visits to the annual UN session in recent memory, and he will be off to the election battleground state of Ohio on Wednesday.
Despite Obama's latest international woes, administration officials are heartened by Romney's own recent foreign-policy stumbles and doubt the president's critics will gain traction in a campaign that remains focused mainly on the US economy.
Fallout from Arab spring
Obama will take the UN podium after a wave of Muslim anger over an anti-Islam movie swept the Middle East, North Africa and South Asia, and an attack on the US Consulate in Benghazi, Libya, claimed the lives of the ambassador and three other Americans.
This has confronted Obama with the worst setback yet in his efforts to keep the Arab Spring revolutions from turning sharply against the United States - and has underscored that he has few good options to prevent it.
The unsettled climate surrounding Obama's UN visit will be a stark reminder that the heady optimism that greeted him when he took office promising to be a transformational statesman has cooled.
US President Barack Obama point to people on the South Lawn of the White House in Washington. AP Photo/Carolyn Kaster
Obama, in his speech, will face the delicate task of articulating US distaste for insults to any religion while at the same time insisting there is no excuse for a violent reaction - a distinction rejected by many devout Muslims.
"It's a real moment for the United States to assert its values and its leadership role," White House spokesman Jay Carney said.
Obama's UN visit also comes at a time of mounting tensions over Iran's nuclear program.
He has refused demands from Israeli Prime Minister Benjamin Netanyahu to set an explicit "red line" for Tehran. Signaling that a rift remains between the two close allies, Obama said in a interview with CBS's "60 Minutes" program that he would ignore "noise that's out there" and make decisions based on U.S. interests.
Underscoring the depth of the problem, Iranian President Mahmoud Ahmadinejad said in New York on Monday that Israel has no roots in the Middle East and would be "eliminated," ignoring a UN warning to avoid his usual incendiary rhetoric ahead of the annual general assembly session.
The White House quickly dismissed the comments by Ahmadinejad, who will address the assembly on Wednesday, as "disgusting, offensive and outrageous."
Obama will use his speech to renew a warning that Iran will not be allowed to acquire nuclear weapons, and his words will be scrutinised to see how far he goes in sharpening his tone.
Netanyahu has shown growing impatience over Obama's entreaties to hold off on attacking Iran's nuclear sites to give sanctions and diplomacy more time to work. Iran denies seeking a nuclear bomb.
At the same time, Obama has come under pressure over his cautious approach to the bloody crisis in Syria, where Assad has defied calls to step aside. Obama could use his address to again denounce China and Russia for blocking further UN measures.
Campaigning in Colorado, Romney argued that the United States should not be "at the mercy" of events in the Muslim world. "We want a president who will shape events in the Middle East," he said.
Aides insist foreign policy is still a bright spot for Obama. The White House never tires of touting the killing of Osama bin Laden and the ending of the Iraq war. But his record appears to have dimmed a bit with a recent run of bad news.
Still, Romney may have a hard time reaping dividends.
Obama at the UN, in shadow of campaign politics
Obama will spend only a day in New York before heading back to the campaign trail against Mitt Romney. There will be none of the normal meetings with world leaders. Still, the White House insists the speech will go further than domestic politics. "This is not a campaign speech," said White House spokesman Jay Carney.
"This is a speech in which the President will make clear his views, the administration's positions and America's role with regards to a lot of transformation that's happening in the world."
While the UN assembly is traditionally a forum for a US President to address the world, Obama's speech this year will still have a domestic undercurrent because of Romney's election attacks on his foreign policy.
In his final international address before the November election, Obama on Tuesday has a United Nations stage afforded to Presidents, not Presidential challengers. He will use it to try to boost his political standing without mentioning his opponent.
There is no doubt that the US Presidential campaign hangs heavy over Obama's speech.
Obama and his rival will also separately address the Clinton Global Initiative, the annual meeting of former president Bill Clinton's humanitarian foundation.
Republican Presidential candidate Mitt Romney walks to his campaign plane in Denver, Colorado. Reuters/Brian Snyder
Romney on Monday accused Obama -- who on Sunday spoke of "bumps in the road" following Arab Spring revolutions -- of minimizing the murder of four Americans including US ambassador to Libya Christopher Stevens in Benghazi.
"When the president was speaking about bumps in the road he was talking about the developments in the Middle East and that includes an assassination," Romney told NBC News.
"It includes a Muslim Brotherhood individual becoming president of Egypt, it includes Syria being in tumult, it includes Iran being on the cusp of having nuclear capability, it includes Pakistan being in commotion."
Polls show Obama is favored over Romney to handle foreign policy, but the Democratic narrative has been complicated by events at the US consulate in Benghazi and wider anti-American fury rocking many Muslim nations.
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Obama brushes off Israeli pressure over Iran
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(With inputs drom AFP, AP)