WASHINGTON – Declaring America “must do a better job of engaging the Muslim world,” Secretary of State Rice introduced former presidential adviser Karen Hughes yesterday as the Bush administration’s choice for a State Department post designed to change Islamic perceptions about America.

Ms. Hughes, pending confirmation by the Senate, would become undersecretary of state for public diplomacy with the rank of ambassador.

“I’m eager to listen and to learn,” Ms. Hughes said, with Ms. Rice standing at her side.

From the White House, President Bush said “spreading the universal principle of human liberty” is key to changing the conditions that spawn terrorism and thus a crucial part of the nation’s long-term security strategy.

“This will require an aggressive effort to share and communicate America’s fundamental values while respecting the cultures and traditions of other nations,” Mr. Bush said in a statement. “Karen Hughes has been one of my most trusted and closest advisers and she has the experience, expertise and judgment to lead this critical effort.”

Choosing one of his most trusted aides “signifies my personal commitment to the international diplomacy that is needed,” Mr. Bush said.

Introducing Ms. Hughes at the State Department, Ms. Rice said America must do much more to counter the “hateful propaganda” that is so common in the Islamic world.

Ms. Rice said Ms. Hughes believes strongly that America “must mobilize young people around the world to shatter the mistrust of past grievances and to foster a new spirit of tolerance and mutual respect.”

Also in attendance at the ceremony was Dina Powell, an Egyptian-born former White House aide who is slated to be a top aide to Ms. Hughes.

Ms. Hughes, who for years has had a major voice in crafting Mr. Bush’s domestic message, is a former counselor to the president who left the White House in 2002 to move her family back to Texas.

She is also a former Texas television reporter. She has continued to advise the president from her home in Austin. Although not a diplomat by training, Ms. Hughes had a hand in several foreign policy initiatives during Mr. Bush’s first term, including efforts to promote democracy and improve the lives of women and children in Afghanistan.

Ms. Hughes and Ms. Powell will focus on Mr. Bush’s plan to spread democracy in the Middle East, an effort that has gained momentum with recent elections in Iraq and the Palestinian territories.

The two nominees are the latest close Mr. Bush aides to follow Ms. Rice to the State Department. Ms. Rice was Mr. Bush’s White House national security adviser during his first term. She succeeded Colin Powell as the top U.S. diplomat in January.