President-elect Barack Obama officially selected New York junior Senator Hillary Clinton as his secretary of state Monday, along with other members of his national security team.

Obama made the announcement at a news conference Monday morning in Chicago.

The president-elect has said his former rival would bring instant stature and credibility to United States diplomatic relations.

"I have known Hillary Clinton as a friend, a colleague, a source of counsel, and as a campaign opponent," Obama said. "She possesses an extraordinary intelligence and toughness, and a remarkable work ethic. . . She is an American of tremendous stature who will have my complete confidence; who knows many of the world’s leaders; who will command respect in every capitol; and who will clearly have the ability to advance our interests around the world."

Clinton said that her decision to leave the Senate behind was a difficult one, and she thanked New Yorkers for allowing her to serve for the past eight years.

"And also you've helped me prepare me for this new role," she said. "After all, New Yorkers aren't afraid to speak their minds and do so in every language."

New York's senior senator, Charles Schumer, was among the first to offer his support of Obama's selection, saying, however, that Clinton will be missed.

"I think New Yorkers, certainly I, will miss her as she moves on to a new position," he said. "But you know we live in a changing world as the events in Mumbai showed and to have someone of her experience, her intelligence, her roll-up-the-sleeves attitude and get the job done is so important to this country in this point and time."

Clinton said that if confirmed she is ready to take on the new position.

"By electing Obama the American people have demanded not just a new direction at home, but a new effort to renew America's standing in the world as a force for positive change," said Clinton. "We know our security values and interests cannot be protected and advanced by force alone or Americans alone. We must pursue vigorous diplomacy using all the tools we can muster to build a future with more partners and fewer adversaries, more opportunities and fewer dangers."

As part of the deal to appoint the former first lady, former president Bill Clinton has agreed to disclose the list of contributors to his foundation as well as his speaking schedule. Officials say he will also refuse contributions from foreign governments.

Obama also announced the appointment of Retired Marine General James Jones for national security advisor, Susan Rice for United Nations ambassador, New York-native Eric Holder for attorney general, and Arizona Governor Janet Napolitano for homeland security secretary.

"They share my pragmatism about the use of power, and my sense of purpose about America’s role as a leader in the world," said Obama.

President George W. Bush appointee Robert Gates was nominated to stay on as secretary of defense.

"I am deeply honored that the president-elect has asked me to continue as secretary of defense," said Gates. "Mindful that we are engaged in two wars and face other serious challenges at home and around the world, and with a profound sense of personal responsibility to and for our men and women in uniform and their families, I must do my duty – as they do theirs. How could I do otherwise?"

The president-elect said he selected the appointees because of their strong personalities but that he will have the final word on policy.

Search For Clinton's Replacement Underway

Meanwhile, Governor David Paterson says he still has not picked a successor for Clinton's Senate seat – and said he will not do so until the position is "officially vacant."

The governor says he needs time to consult with former senators and people around the state before making his decision.

A few names have been floated as possible replacements – including State Attorney General Andrew Cuomo, Congresswoman Nydia Velazquez, and upstate Representative Kirsten Gillibrand.

In response to Clinton's selection, Velazquez said that "whoever succeeds her will have their work cut out for them."

Paterson is set to meet with Obama in Philadelphia tonight, as part of a Democratic governors' meeting. The leaders are in town for the National Governors Association conference, which begins tomorrow.

Obama is scheduled to deliver a speech on the economy.

Paterson held a news conference this afternoon, though he did not address who is in the running as Clinton's replacement.