WASHINGTON — Secretary of State-designate Hillary Rodham Clinton on Tuesday promised a new diplomacy that would give America "more partners and fewer adversaries" and signaled her intention to reach out to Iran and continue the uphill struggle for Middle East peace.

At a five-hour Senate confirmation hearing, Clinton said she and President-elect Barack Obama would overhaul the approach of the Bush administration with a rejuvenated emphasis on diplomatic engagement, alliance-building and development.

"I believe that American leadership has been wanting but is still wanted," she told the Senate Foreign Relations Committee. She said U.S. foreign policy should not be guided by "rigid ideology," pledging that in the Obama administration, "there will be no doubt about the leading role of diplomacy."

Clinton wants to increase State Department funding swiftly to broaden its role in national security and increase the government's reliance on nonmilitary action in response to international crises. That objective is shared by her Pentagon counterpart, Defense Secretary Robert M. Gates.

Yet on a series of international problems, Clinton described a posture with echoes of the Bush administration. "We will lead with diplomacy because it's a smart approach," she said at one point. "But we also know that military force will sometimes be needed."

She was received warmly but faced repeated challenges about the charitable activities of her husband. Democratic as well as Republican senators expressed concern that contributions to former President Bill Clinton's foundation could pose potential conflicts of interest.

Sen. Richard G. Lugar of Indiana, the committee's senior Republican, urged the Clinton foundation to exclude all foreign donations. He said the foundation represented a "unique complication" because of the risk that foreigners may believe giving money will win favors from the former president's wife.

Hillary Clinton defended her husband, contending that plans for disclosure of contributors go beyond that required by government ethics watchdogs. "No matter what we do, there will be those that (claim) conflicts," she said.

Sen. John F. Kerry, D-Mass., the new chairman of the committee, said Lugar's concerns were shared by the others on the panel. Kerry said he plans to hold a committee vote this week, and Hillary Clinton is expected to win confirmation easily. The former Democratic presidential contender plans to resign her post as New York's junior senator after she is confirmed.

Often considered a polarizing figure, Clinton, 61, debuted in her State Department role at a time of rising public approval. A Gallup poll Tuesday showed 65 percent of Americans hold a favorable opinion of her, the highest such rating in nearly 10 years.

She appeared with her daughter, Chelsea, who sat directly behind her. The former president stayed away to ensure attention remained focused on his wife, a spokesman said.

Hillary Clinton spoke easily about a range of thorny problems worldwide, addressing the war between Israel and Hamas in the Gaza Strip for the first time. She acknowledged that problems in the Middle East may seem intractable but said: "We cannot give up on peace."

"The president-elect and I understand — and are deeply sympathetic to — Israel's desire to defend itself under current conditions and to be free of shelling by Hamas rockets," she said. "However, we have also been reminded of the tragic humanitarian costs of conflict in the Middle East and pained by the suffering of Palestinian and Israeli civilians."

Clinton echoed the Bush administration stand in part by declaring: "You cannot negotiate with Hamas until it renounces violence, recognizes Israel and agrees to abide by past agreements. That is just for me an absolute. That is the United States government's position; that is the president-elect's position."

Clinton offered no specifics on how she will try to end the fighting between Israel and Hamas, a task she will confront as soon as she takes office.

Elsewhere, she expressed Obama's view on the need for a diplomatic overture to Iran as well as new contacts with Syria. But she demurred when asked for specific plans and emphasized the incoming administration does not intend to ease pressure on Iran to halt its nuclear program.

And there too she echoed the Bush administration in referring to the possibility of military action, saying "no option is off the table."

She noted Obama has described the possibility of an Iranian atomic bomb with the same term used by Bush: "unacceptable."

She said six-nation negotiations concerning North Korea organized by the Bush team "is a framework that the president-elect and I believe works."

On Iraq, Clinton seemed to be preserving her options when asked by Sen. Russell D. Feingold, D-Wis., about plans to remove all U.S. combat troops within 16 months. Clinton said Obama intends to remove combat troops "safely and responsibly, as soon as possible." She said troops would be moved out of cities and towns "hopefully by June."

She said an expanded U.S. diplomatic corps could take on jobs around the world that in recent years have fallen to the much larger Pentagon. Clinton, Gates and other current and former government officials believe that in many countries, foreign service officials can perform nonmilitary jobs more efficiently and less expensively.

While repeatedly criticizing Bush, she had warm words for the outgoing president in some areas, praising his work for world AIDS relief and citing first lady Laura Bush's initiative on human rights for Afghan women.