U.S. President Barack Obama said on Tuesday the political upheaval sweeping the Arab world made it "more vital than ever" to revive long-stalled peace negotiations between Israel and the Palestinians.

Speaking after talks with Jordan's King Abdullah at the start of a week of intense Middle East diplomacy, Obama pledged to keep pressing for a two-state solution to the conflict, despite his failed efforts so far and dim prospects for a renewed peace drive.

Obama, who is seeking to reconnect with an Arab world showing signs of frustration with his approach to the restive region, offered no new ideas for advancing the peace process.

The president plans to deliver a major policy speech on the "Arab spring" uprisings on Thursday, meet Israeli Prime Minister Benjamin Netanyahu on Friday and address an influential pro-Israel lobbying group on Sunday.

With Jordan's monarch at his side, Obama insisted that unrest convulsing the region offered a chance for Israelis and Palestinians to restart talks broken off last year in a dispute over Israeli settlement building in the occupied West Bank.

"Despite the many changes -- or perhaps because of the many changes that are taking place in the region -- it's more vital than ever that both Israelis and Palestinians find a way to get back to the table," he told reporters.

Obama is struggling to counter Arab perceptions of an uneven U.S. response to a wave of popular uprisings and disarray in his Israeli-Palestinian peace strategy. He hopes to use the U.S. killing of Osama bin Laden, which for now has boosted his standing at home and abroad, as a chance to reach out to a large Arab audience.

MIDDLE EAST UNREST

Obama and Abdullah also sought common ground on the unrest that has gripped the Arab world, toppling autocratic U.S. allies in Egypt and Tunisia and engulfing Libya in civil war.

Jordan has faced protests demanding curbs on the king's powers but not nearly of the magnitude confronting Syria, Yemen and Bahrain. The king replied in March by sacking his unpopular prime minister and promising constitutional changes.

Trying to show that reform efforts by Washington's autocratic Arab allies will not go unrewarded, Obama praised Abdullah and pledged to help Jordan with fresh economic aid.

At the same time, Washington ratcheted up pressure on Syrian President Bashar al-Assad, threatening new sanctions over his violent crackdown. Human rights groups have criticized Obama for not taking tougher action against Syria, a U.S. foe.

Obama has taken a cautious line, expressing support for democratic aspirations in the region while trying to avoid upsetting longtime partnerships seen as crucial to fighting al Qaeda, containing Iran and securing vital oil supplies.

The king, a U.S. ally and key player in past peace drives, made clear he wanted a renewed push by Obama. Jordan and Egypt are the only Arab states with peace treaties with Israel.

"We will continue to partner (with Jordan) to try to encourage an equitable and just solution to a problem that has been nagging the region for many, many years," Obama said.

NO NEW INITIATIVE

But Obama, whose attempts to broker a peace deal have yielded little since he took office, has no plans to roll out a new initiative during the latest diplomatic flurry, aides say.

Many Israelis are already unsettled over the implications for the Jewish state from unrest in the broader Middle East, and a new reconciliation deal between the mainstream Palestinian Fatah faction and its rival, the Islamist Hamas movement, has raised further doubts about peace prospects.

Netanyahu said on Monday a Palestinian unity government that includes Hamas -- which Israel and the United States brand a terrorist group --- could not be a peace partner.

The risk for Obama is that pushing Israel for concessions could alienate the Jewish state's base of support among the U.S. public and in Congress as he seeks re-election in 2012. Obama has already had strained relations with Netanyahu.

Obama, speaking later at a White House reception marking Jewish American Heritage Month, reaffirmed "unshakable support and commitment" to Israel.

But in the absence of progress on the diplomatic track, the Palestinians are threatening to seek the U.N. General Assembly's blessing for a Palestinian state in September, a path that alarms Israel and is opposed by Washington.

Signaling doubts on any renewed U.S. effort, Palestinian President Mahmoud Abbas wrote in a New York Times opinion piece on Tuesday that U.N. recognition would enable his government to negotiate "from the position of one United Nations member whose territory is militarily occupied by another."

Deadly clashes on Israel's borders on Sunday underscored the depth of Arab anger at Israel. The resignation of Obama's Middle East envoy, George Mitchell, raises further questions about peace prospects.