In his first working day at the White House on Wednesday, US President Barack Obama had a full schedule, handling important and tough issues including the economy, Iraq war, Guantanamo prison, among others.

After a grand inaugural ceremony and 10 official celebration balls on Tuesday, Obama officially moved into the Oval Office around 8:30 a.m. EST (1330 GMT). Later in the day, he attended a religious service at the National Cathedral, as all new U.S. presidents do.

Topping his agenda was a series of calls to Middle East leaders, including Egyptian President Hosni Mubarak, Israeli Prime Minister Ehud Olmert, Jordan's King Abdullah and Palestinian leader Mahmoud Abbas to show his concern and commitment to the peace process in the region.

During the recent conflict between Israel and Hamas, Obama chose to say nothing as he was only the president-elect at the time.

"He used this opportunity on his first day in office to express his commitment to active engagement in pursuit of Arab-Israeli peace," White House spokesman Robert Gibbs said.

Obama spent the rest of the day dealing with immediate challenges facing the United States -- the pullout of U.S. troops from Iraq and economic recovery.

In a meeting with the U.S. ambassador to Iraq, the U.S. military commander in Iraq, and top cabinet and national security officials via a video teleconference, he said he had already instructed top military commanders to "engage in additional planning necessary for a responsible withdrawal" of American troops from Iraq.

During his presidential campaign, Obama vowed to pull out American combat troops from Iraq in the first 16 months of his presidency, and shift resources from Iraq to Afghanistan, the prime front of the anti-terror war.

Obama also took action to fulfill his promise to get the country out of its economic woes by calling in his top economic advisors to discuss an economic stimulus package estimated to be worth 825 billion U.S. dollars.

The new U.S. president issued executive orders to start the process of closing Guantanamo prison where terrorist suspects are detained.

The orders require a systematic review of detention policies and procedures, and of all individual cases to decide "whether and how such individuals can and should be prosecuted."

Taking a second oath

Apart from major issues, Obama also signed new rules to ban gifts by lobbyists to anyone serving in the administration, and imposed a pay freeze for about 100 White House aides who earn 100,000 dollars or more.

"The way to make government responsible is to hold it accountable," Obama said.

Obama also took a second oath of office to correct a slight initial mistake.

According to the U.S. Constitution, the oath should read: "I do solemnly swear (or affirm) that I will faithfully execute the office of President of the United States, and will to the best of my ability, preserve, protect, and defend the Constitution of the United States."

However, Chief Justice of the Supreme Court John Roberts said: "I will execute the office of President of the United States faithfully," leading Obama to make the same mistake when repeating the oath.

"Because there was one word out of sequence, Chief Justice Roberts administered the oath a second time," the White House said.

(Xinhua News Agency January 22, 2009)