President Obama traveled to the State Department yesterday afternoon for a visit that was as rich in symbolism as in substance, underscoring his pledge to give top priority to diplomacy as he outlined an activist policy in the Middle East and warned that "difficult days lie ahead" in Afghanistan.

Obama and Vice President Biden stood to one side as Secretary of State Hillary Rodham Clinton announced new special emissaries on the most intractable national security problems -- Richard C. Holbrooke for Afghanistan-Pakistan and George J. Mitchell for the Middle East -- to an invited gathering of several hundred, including State Department officials. Just hours earlier, about 1,000 cheering civil service and Foreign Service employees had packed the building's lobby to welcome her on her first day at work.

Clinton called the appointments of Holbrooke and Mitchell "a loud and clear signal . . . that our nation is once again capable of demonstrating global leadership in pursuit of progress and peace." Obama said the two statesmen would "convey our seriousness of purpose" in dealing with challenges he described as complex and urgent.

The new secretary, and the new president's choice to make State his first Cabinet department stop -- even before his maiden trip to the Pentagon -- buoyed a workforce that often felt disdained and relegated to the back seat behind the military over the past eight years. "People were just elated that the president came here and said all the right things about strengthening diplomacy," one official said.

"It is my privilege to come here and to pay tribute to all of you, the talented men and women of the State Department," Obama said. "I've given you an early gift, Hillary Clinton," he said, adding that she has "my full confidence."

Both the new appointees are experienced negotiators. Holbrooke, a former Foreign Service officer who led the U.S. team that brokered the 1995 Dayton peace accords in the Balkans, was a leading supporter of Clinton's presidential campaign. Mitchell, a former Maine senator, chaired negotiations that led to the 1998 Good Friday agreement ending decades of conflict in Northern Ireland, and a high-level commission on the Israeli-Palestinian conflict in 2000-01.

Obama has criticized the Bush administration as lacking high-level involvement in the Middle East, but he broke little new policy ground in his first extensive remarks on the situation yesterday. He said he was "deeply concerned by the loss of Israeli and Palestinian life . . . and by the substantial suffering and humanitarian needs" in the Gaza Strip, where three weeks of fighting between Hamas militants and the Israeli military halted last weekend with a still-fragile cease-fire.

He called on Hamas to renounce violence, abide by past agreements and recognize Israel's right to exist, and said Israel should open the territory's borders. He cited "constructive elements" in an Arab peace initiative but said "now is the time for Arab states to act on the initiative's promise" by supporting the Palestinian Authority government, ousted from Gaza by Hamas in 2007, normalizing relations with Israel and "standing up to extremism that threatens us all."

Palestinian activists noted that Obama made no reference to the expansion of Israeli settlements in the West Bank but said they were ecstatic over the selection of Mitchell, who is well remembered for firmly recommending an end to Israeli settlement activity in his 2001 report.

Ghaith al-Omari, a former adviser to Palestinian Authority President Mahmoud Abbas, said "the policies are the same" but "Obama signaled early engagement and an energetic approach." Mitchell proved in his earlier engagement with the issue that "he is not a pushover," Omari said. "He was tough on the Palestinians but tough on the Israelis too."

Mitchell, who plans to travel to the region the first week of February, said he did not "underestimate the difficulty of this assignment." But his Northern Ireland experience, he said, had convinced him that "there is no such thing as a conflict that can't be ended."

Clinton said Holbrooke's broader mandate, centered on Afghanistan and Pakistan, will be to "coordinate across the entire [U.S.] government an effort to achieve United States' strategic goals in the region." He, too, plans to travel to his new area of responsibility early next month.

Calling it a "daunting assignment," Holbrooke said that "nobody can say the war in Afghanistan has gone well." Husain Haqqani, Pakistan's ambassador to the United States, praised the appointment, saying Holbrooke "brings tremendous experience and knowledge, and proven diplomatic skills."

Obama has said that President George W. Bush spent too much attention and resources on Iraq at the expense of the Afghan war, and yesterday he described the situation in Afghanistan as "perilous." He said his administration has begun an overall strategic review of policy in the region and will "set clear priorities in pursuit of achievable goals."

At a Pentagon news conference yesterday, Defense Secretary Robert M. Gates said the "goals we did have for Afghanistan are too broad and too far into the future. We need more concrete goals that can be achieved realistically within three to five years, in terms of reestablishing control in certain areas, providing security for the population, going after al-Qaeda, preventing the reestablishment of terrorism."

Adm. Michael Mullen, the chairman of the Joint Chiefs of Staff, who appeared with Gates, also said Obama had been provided with several options for withdrawing troops from Iraq, including implementation of a 16-month timeline for the departure of combat troops.

At Clinton's State Department arrival ceremony early yesterday, she told cheering staffers that she was "absolutely honored and thrilled beyond words to be here." She was flanked by Steve Kashkett, the State Department representative for the Foreign Service union, and William J. Burns, the undersecretary of state for political affairs and the highest-ranking career officer.

Kashkett did not mince words on his feelings about the previous administration, telling Clinton that "both you and the president have decried the neglect that the Foreign Service and the State Department as a whole have suffered in recent years. No one knows better than the people in this room and their colleagues posted all over the world how true that is.

"So far," Kashkett added, "we are thrilled to have you here."

To laughter, Clinton thanked him for his candor, adding, "This is not going to be easy."