Washington - US Secretary of State Hillary Clinton promised a renewed focus on diplomacy and development aid as tools of US foreign policy during a welcoming ceremony Thursday at the State Department.

"This is going to be a great adventure," she told the crowd of civil service staff that cheered wildly in the lobby of the building, one day after she was confirmed by the US Senate and sworn in as the country's top diplomat.

Clinton said President Barack Obama has set the new tone and promised a new spirit of cooperation in his inaugural speech on Tuesday.

"I believe with all of my heart that this is an new era for America," Clinton said. "We will make clear as we go forward that diplomacy and development are essential tools in achieving the long term objectives of the United States."

The US Senate voted overwhelmingly Wednesday to confirm Clinton as secretary of state, clearing the way for her to take the reins of US foreign policy as Obama moves quickly to address a host of international challenges.

Clinton will have to deal with pressing issues including the Iranian and North Korean nuclear programmes, the Israeli-Palestinian conflict, as well as wars in Iraq and Afghanistan.

"This is not going to be easy," she told her new staff. (dpa)