“We must use American diplomacy to help create a balance of power in the world that favors freedom,” Ms Rice, 50, told the Senate Foreign Relations Committee.
“And the time for diplomacy is now.”
She praised the leadership of President Bush in the aftermath of the 11 September 2001 attacks - “a defining moment for our nation and the world”.
“Under the vision and leadership of President Bush,” she said, “our nation has risen to meet the challenges of our time: fighting tyranny and terror, and securing the blessings of freedom and prosperity for a new generation.”
“Now is the time to build on these achievements to make the world safer, and to make the world more free,” she said.
But she indicated that the US would not let traditional allies or multilateral institutions stand in the way of “effective” action by Washington.