Secretary of State Colin Powell Wednesday swore in veteran diplomat John Negroponte, the former U.S. ambassador to the United Nations, to be the Bush administration's first envoy to Iraq. Mr. Powell said the creation of a U.S. embassy in Baghdad and the end to the Coalition Provision Authority June 30 will mark the "unequivocal end" to the U.S.-led occupation.

The swearing-in of an ambassador is normally a low-key affair. But the departure of the U.S. Iraq administrator Paul Bremer and the opening of a U.S. embassy headed by Mr. Negroponte is of key political importance to the Bush administration. And the ceremony for the new envoy was a major televised event, attended by among others foreign ambassadors, members of Congress and White House National Security Adviser Condoleezza Rice.

Secretary of State Powell said the United States is keeping its promise to return full sovereignty to the Iraqi people, and that the "unequivocal end" to the occupation is just one week away.

He acknowledged that the military mission of the United States and its allies in Iraq doesn't end next week and that coalition forces will stay on to provide security until Iraqis can assume the responsibility for themselves.

But he said administrator Bremer will turn over control of the country to the Iraqi interim government and depart, while Mr. Negroponte, due to arrive in early July, will assume a more traditional role as U.S. envoy to the Baghdad authorities.

"I'm confident that we'll be remaining in the closest of partnership with Iraqi authorities in the months ahead," said Mr. Powell. "We may not agree on everything. They are now sovereign. But that's normal. We've never sought an Iraq that was our client or dependency, quite the contrary. Ambassador Negroponte will guide our cooperation and will smooth out any differences that may arise, as all of the president's envoys do wherever they serve around the world."

Mr. Negroponte, the U.S. ambassador to the United Nations for nearly three years, helped win approval for several crucial Security Council resolutions on Iraq.

But he said that none was more important than the last one, resolution 1546 approved earlier this month, which endorsed the interim government in Baghdad and plans for a directly-elected government by the end of next year.

Mr. Negroponte said his aim as ambassador will be to help assure that this internationally-supported vision for Iraq is fulfilled.

"As I prepare to go to Iraq as United States ambassador, I do so with a clear mission: to offer support and assistance to the Iraqi people and government as Iraq reasserts its full sovereignty," he said. "Three mutually-reinforcing objectives underpin this goal: establishing security by helping the Iraqis defeat terrorists and criminal elements who oppose a free Iraq, promoting economic development, and supporting Iraq's democratization through elections, promotion of human rights, and the rule of law."

Mr. Negroponte said the project will require many months and many years, but that "time will be our friend, as we stay the course."

Baghdad will be the fifth U.S. overseas mission Mr. Negroponte has headed in a 44-year diplomatic career but it will be by far the largest, with an estimated 900 Americans in the embassy staff along with several hundred Iraqi employees.

The U.S. embassy will temporarily occupy one of the former Iraqi government buildings in Baghdad's "green zone" while a permanent mission is negotiated for and constructed, a process expected to take at least three years.