U.S. President Barack Obama on Wednesday called four Middle East leaders, including Prime Minister Ehud Olmert and Palestinian President Mahmoud Abbas, to express his commitment to be actively engaged in the path toward Middle East peace.

The White House said in a statement that Obama was determined to help consolidate a cease-fire in the Gaza Strip, and would pursue an active role in reaching a Middle East settlement.

During their phone conversation, Obama promised Olmert that he would work together with Israel to halt the smuggling of weapons into the Gaza Strip. Olmert, meanwhile, congratulated Obama on his inauguration and said that the ceremony had very much touched all of Israel.

Olmert also updated Obama on the situation in the Gaza Strip, following Israel's three-week offensive there. Olmert told Obama that preventing Hamas from rearming was critical to "stabilizing the ceasefire and promoting the diplomatic process between Israel and the Palestinian Authority", Olmert's office said in a statement.

The prime minister also told Obama that Israel would make every effort to ensure that humanitarian aid entered the Gaza Strip and would work to help improve the economic situation there.

An aide to Abbas said Wednesday that Obama had called him to express his commitment to achieving peace in the Middle East.

Wednesday's call fulfills a promise by Obama to get involved in Mideast peacemaking from day one of his presidency.

"Obama reiterated that he and his administration will work in full partnership with President Abbas to achieve peace in the region," said Saeb Erekat, a senior Palestinian negotiator in peace talks with Israel.

Obama also called Egyptian President Hosni Mubarak and Jordanian King Abdullah II.

"[Obama] used this opportunity on his first day in office to communicate his commitment to active engagement in pursuit of Arab-Israeli peace from the beginning of his term, and to express his hope for their continued cooperation and leadership," The White House said in a statement.

"In the aftermath of the Gaza conflict, he emphasized his determination to work to help consolidate the ceasefire by establishing an effective anti-smuggling regime to prevent Hamas from rearming, and facilitating in partnership with the Palestinian Authority a major reconstruction effort for Palestinians in Gaza."

"He pledged that the United States would do its part to make these efforts successful, working closely with the international community and these partners as they fulfill their responsibilities as well," said the statement. "The President appreciated the spirit of partnership and warm nature of these calls."

Obama summons defense officials to talks future of U.S. wars

Obama plunged on his first day in office into the task of governing a nation he vows to change, calling together U.S. economic and military leaders Wednesday to address America's daunting challenges.

A day after claiming his place in history as the first black U.S. president, Obama is faced with pulling the U.S. economy out of its nosedive even as he moves on his promise to withdraw American forces from Iraq while sending still more soldiers to America's other war in Afghanistan.

In addition to meeting with his advisers, Obama was to welcome public visitors into the White House, while Congress takes a hard look at his economic revival plan and takes up the nominations of Hillary Rodham Clinton as secretary of state and Timothy Geithner for treasury secretary.

"Tonight, we celebrate. Tomorrow, the work begins... Together, I am confident we will write the next great chapter in America's story," Obama declared Tuesday night at the Commander in Chief Ball, one of 10 official inaugural celebrations that kept him and first lady Michelle Obama up into the early morning hours.

Obama's Democratic Party now controls both chambers of Congress and the White House for the first time since 1994, providing a chance for the new administration to succeed if he can work in concert effectively with lawmakers.

A meeting with his economic team was planned to assess his approach and plot the way forward. Taking over the White House with 11 million Americans out of work and trillions of dollars in stock market savings lost, Obama said that turning around the limping economy is his first and greatest priority.

Congress already has given him a second installment of financial-industry bailout money, worth $350 billion, and is fast-tracking a massive economic stimulus bill of $825 billion or more. Even those bold measures, on top of hundreds of billions in other federal spending over recent months, may not be enough to prevent the recession from growing deeper.

"Fortunately we've seen Congress immediately start working on the economic recovery package, getting that passed and putting people back to work," he said in an ABC News television interview. "That's going to be the thing we'll be most focused on."

Addressing the war in Iraq that he has promised to end was featuring prominently in Obama's first day as well.

According to officials, Obama will conduct a video teleconference late in the afternoon with members of the National Security Council as well as the U.S. military commanders in the two war zones.

Obama has said he wants U.S. combat troops out of Iraq in 16 months, as long as doing so would not endanger either the Americans left behind for training and terrorism-fighting or the security gains in Iraq. He has said he would use that drawdown to bolster the U.S. presence in Afghanistan, where a resurgent Taliban has been gaining ground.

In his inauguration speech Tuesday he offered a glimpse of what was to come. "We will begin to responsibly leave Iraq to its people and forge a hard-earned peace in Afghanistan," he said.

Summoned to the White House to discuss the way ahead in the wars were Defense Secretary Robert Gates - the lone Republican Cabinet holdover from the Bush administration - along with chairman of the Joint Chiefs of Staff, Adm. Mike Mullen; the top military commander in the Middle East, Gen. David Petraeus, and other members of the security council.

Participating from the war front were to be Gen. Ray Odierno, the top U.S. commander in Iraq, and Gen. David McKiernan, the top commander in Afghanistan, according to two senior military officers.

The officials spoke on condition of anonymity because the meeting has not been officially announced by the White House.

While Obama gets to work in earnest at the White House, Congress planned to do its part.

A Senate committee was scrutinizing Obama's $825 billion economic revival package. On the other side of the Capitol, the House planned a vote on legislation setting conditions on Obama's use of the new infusion of $350 billion in financial bailout money.

Getting the Obama administration fully staffed also was proceeding. Within hours of Obama's swearing in, the Senate approved six members of his Cabinet.

His choice of Clinton to be secretary of state awaited a Senate vote Wednesday. Her confirmation was held up for a day by Republican John Cornyn of Texas who raised concern over the foundation fundraising of her husband, the former president.

Also left unconfirmed was Geithner, the nominee to head the Treasury Department. He faces the Senate Finance Committee, also Wednesday, where he will have to explain his initial failure to pay payroll taxes he owed while working for the International Monetary Fund.

The Senate Judiciary Committee could take up the question of Eric Holder for Obama's attorney general.

The new president signaled that a flurry of executive actions, studied and prepared during his two-month-plus transition, should be expected soon.

Among the possibilities for the first day was the naming of a Middle East envoy, critical at a time of renewed hostilities between Israelis and the Palestinians; an order closing the U.S. military prison at Guantanamo Bay, in Cuba, a move that will take considerable time to execute.

The military on Tuesday suspended war crimes trials there pending a review. Also expected was a prohibition of the harsh interrogation techniques that have damaged the U.S. image worldwide.

Preventative action was taken Tuesday, when new White House chief of staff Rahm Emanuel ordered all federal agencies to put the brakes on any pending regulations that the Bush administration tried to push through in its waning days.