HISTORIC OPPORTUNITIES

Palestinian President Mahmoud Abbas welcomed Obama's efforts to renew talks with Israel that collapsed last year in a dispute over Israeli settlement building.

Robert Danin, a Middle East analyst at the Council on Foreign Relations, said that for the first time the United States has "embraced the Palestinian position on borders."

Obama also hailed popular unrest sweeping the Middle East as a "historic opportunity" and said promoting reform was his administration's top priority for a region caught up in unprecedented upheaval. "The people have risen up to demand their basic human rights," he said. "Two leaders have stepped aside. More may follow."

And he ratcheted up pressure on Syrian leader Bashar al-Assad, saying for the first time that he must stop a brutal crackdown or "get out of the way," and prodded US allies Yemen and Bahrain as well for democratic transformation.

While throwing his weight behind the push for reform, Obama did not abandon his approach of balancing support for democratic aspirations with a desire to preserve long-time partnerships seen as crucial to fighting al Qaeda, containing Iran and securing vital oil supplies.

Struggling to regain the initiative in a week of intense Middle East diplomacy, Obama seized an opportunity to reach out to the Arab world following the death of Osama bin Laden at the hands of US Navy SEAL commandos.

He announced billions of dollars in aid for Egypt and Tunisia to support and encourage their political transitions after revolts toppled autocratic leaders.

Obama has scrambled to keep pace with still-unfolding events that have ousted long-time leaders in Egypt and Tunisia, threatened those in Yemen and Bahrain and engulfed Libya in civil war where the United States and other powers have unleashed a bombing campaign.