The Bush administration will "walk a fine line" in seeking punitive international sanctions against Iran's Islamic government over its disputed nuclear program, Secretary of State Condoleezza Rice said Wednesday.

The Bush administration's top diplomat detailed a two-track approach to Iran -- concerted international pressure to deter Tehran from building a bomb, and a newly robust attempt to seed democratic change inside the country with $75 million for broadcasts and aid to dissidents.

Even so, Rice got a mixed reception from theSenate Foreign Relations Committee. She ran into tough questions from lawmakers of both parties about Iran, Iraq, the Palestinians and other issues, but also won praise for accomplishments including a new alliance of world opinion against Iran's nuclear ambitions.

"I don't see, Madame Secretary, how things are getting better. I think things are getting worse. I think they're getting worse in Iraq. I think they're getting worse in Iran," said Sen. Chuck Hagel, R-Neb. He was also pessimistic about the implications of the militant group Hamas' victory in Palestinian elections last month.

On Iraq, the panel's top Democrat countered Rice's optimism about political unity among Iraq's squabbling ethnic groups.

"I'm not hopeful," Sen. Joseph Biden, D-Del., told Rice. "The policy seems not to be succeeding."

Rice gave the most detailed glimpse to date of U.S. options and objectives on Iran, now that the U.N. Security Council is set to consider the case against its nuclear effort. She called the country the single greatest challenge faced by the United States, because of its alleged nuclear ambitions and role as a terrorist patron state.

Under questioning from both Democratic and Republican senators frustrated with Bush administration policies in Middle East trouble spots, Rice acknowledged that the nations trying to keep Iran from building a bomb had divergent views over what to do next.

"It's not easy. There is not a common view on when or how sanctions ought to be taken," Rice said, "but the Iranian regime is giving the world a very good set of reasons to take serious measures."

Rice said the United States is examining the ramifications of "the full range of potential sanctions" the Security Council could levy, but signaled that any initial steps will be small.

That is a tacit acknowledgment that the Bush administration would probably lose support from Iranian allies Russia and China, and perhaps other nations, if it sought tougher action now.

There is little stomach among Security Council members for broad economic sanctions like those imposed on Iraq under Saddam Hussein. Many countries are concerned that those measures could take a greater toll on ordinary citizens than on their government, and might backfire by prompting Tehran to retaliate by boosting its oil prices.

"We want to look at the effect on the international community as a whole of any actions that we take, economies and the like," she said. "I think you will see us trying to walk a fine line in what actions we take."

The United States has long sought Security Council review for Iran, which claims its nuclear program is intended only to produce electricity. The United States and European allies contend Iran is bent on acquiring technology that could be used to build a bomb.

The Security Council could take up the Iran issue as soon as March.

Rice also asked Congress for another $75 million this year to build democracy in Iran, money that would go to dissidents and scholars as well as to fund Farsi language radio and satellite television programming in the mold of the old Radio Free Europe.

"The United States wishes to reach out to the Iranian people and support their desire to realize their own freedom and to secure their own democratic and human rights. The Iranian people should know that the United States fully supports their aspirations for a freer, better future," Rice said.

A State Department official later refused to say whether the money is intended to help an eventual overthrow of the mullah-led government. Official U.S. policy seeks only to change Iran's behavior. The official spoke to a roomful of reporters but insisted on anonymity.

The money comes on top of $10 million already approved by Congress for similar projects this year. Together the sums would represent greater U.S. involvement than has been publicly identified before.

Rice also provided new detail about the future of U.S. aid to the Palestinians under Hamas, which the State Department lists as a terrorist group. Rice said the United States, which for years has provided aid to help the Palestinian people but very little directly to the Palestinian government, would not turn its back on such humanitarian programs as immunizing children against disease.

"But no money will go to that government," Rice said under questioning by Sen. George Allen, R-Va.

"I don't want a penny of taxpayer money going to Hamas," Allen told Rice.

"Neither do I," she replied.

Rice reiterated that message later Wednesday in a private meeting with eight Jewish leaders she invited to the State Department to discuss Hamas and Iran.

Also Wednesday, the House voted 418-1 to pass a symbolic resolution expressing support for halting assistance to the Palestinian government if Hamas continued to advocate the destruction of Israel. The Senate has already approved the nonbinding resolution.