WASHINGTON - US President Barack Obama was scheduled to lay out a new strategy toward a skeptical Arab world on Thursday, offering fresh aid to promote political change as he seeks to shape the outcome of popular uprisings threatening both friends and foes.

In his much-anticipated "Arab spring" speech, Obama was expected to reset relations with the Middle East, but his outreach could falter amid Arab frustration over an uneven US response to the region's revolts and his failure to advance Israeli-Palestinian peacemaking.

Obama was expected to unveil new economic aid packages to bolster political transitions in Egypt and Tunisia, nudge allies like Yemen and Bahrain to undertake reforms and harden his line against Syrian President Bashar al-Assad.

Struggling to regain the initiative in a week of intense Middle East diplomacy, Obama is seizing what the White House called a "window of opportunity" in the wake of the death of Osama bin Laden at the hands of US Navy SEALs.

"Having wound down the Iraq war ... and having taken out Osama bin Laden, we are beginning to turn the page to a more positive and hopeful future for US policy in the region," a senior administration official told reporters in previewing parts of the president's speech.

Obama aimed to articulate a more coherent approach for dealing with unprecedented political upheaval that has swept the Middle East and North Africa in recent months, upending decades of US diplomatic assumptions.

His speech at the State Department was meant to counter criticism that he has been slow and inconsistent in responding to the swirl of events.

But he was not expected to stray far from his approach of balancing support for democratic aspirations with a desire to preserve longtime partnerships seen as crucial to fighting al-Qaida, containing Iran and securing vital oil supplies.

However, the risk for Obama is that his policy blueprint, calibrated for an audience ranging from the Arab masses to Middle Eastern leaders to the American public and lawmakers, will be too vague and nuanced to satisfy any of them.

Easier to predict is that he will stoke Arab disappointment with what will be left out - fresh US proposals for breaking the impasse between Israel and the Palestinians.

The decades-old conflict remains a central preoccupation of the Arab world.

While Obama will renew his call for the two sides to return to the table after talks broke down late last year over Israeli settlement building in the occupied West Bank, his push is not expected to be forceful enough to revive negotiations.

Reuters