Secretary of state designate Hillary Clinton Tuesday promised a "smart" blend of U.S. military and diplomatic power projection under Barack Obama, and said America must never give up on Middle East peace. In the latest twist to her trail-blazing political career, Clinton got a warm embrace from the Senate Foreign Relations committee in her confirmation hearing, and laid out the first building blocks of the new U.S. foreign policy. As Israel's war on Hamas in Gaza rages, she ruled out talks with the Islamist militant group but expressed disquiet over civilian casualties on both sides. She also previewed an "aggressive" bid to halt North Korea's alleged proliferation activities, and promised the United States would belatedly throw itself into the fight against global climate change. "I believe American leadership has been wanting, but is still wanted," said Clinton, who narrowly lost her campaign against Obama for the Democratic nomination last year, ending her bid to be the first woman president. "We must use what has been called 'smart power,' the full range of tools at our disposal," Clinton said, advocating a mix of diplomatic, economic, military, political legal and cultural strategies. In a dig at the Bush administration, Clinton said she and Obama believed in foreign policy which married "principles and pragmatism, not rigid ideology." But, Clinton, who is expected to cruise towards confirmation, warned that military power "will sometimes be necessary ... as a last resort." Clinton reiterated Obama's pledges to put a new focus on the war in Afghanistan and to withdraw US troops from Iraq. She said the Obama administration, which takes office Jan. 20, will try a "new approach" by using diplomacy towards Iran but no option was being taken off the table, even apparently military might, to stop Tehran going nuclear. Clinton pledged the United States would work to combat climate change, in a reversal of the President George W. Bush administration's reticence to throw itself into global efforts. Touching on the Gaza conflict, Clinton, set to succeed Condoleezza Rice at the State Department, said the United States "cannot give up on peace." "The president-elect and I understand and are deeply sympathetic to Israel's desire to defend itself under the current conditions, and to be free of shelling by Hamas rockets," Clinton said. The former first lady also promised a "comprehensive" terrorism strategy to root out Al-Qaeda, and like the Bush administration, warned the greatest threat to America was that weapons of mass destruction would fall into the hands of terrorists. She said the Obama administration would seek to reduce global nuclear stockpiles and proliferation. Clinton, who spoke scathingly of Beijing's trade policies during her campaign, warned that China-U.S. ties would depend largely on Beijing's behavior. "We want a positive and cooperative relationship with China, one where we deepen and strengthen our ties on a number of issues," Clinton said. "But this is not a one-way effort - much of what we will do depends on the choices China makes about its future at home and abroad." She also said Obama wanted a cooperative relationship with Russia, after recent spats between Washington and Moscow, but would stand up for its interests and international norms. The only note of discord came in a courteous but forceful warning from Republican Senator Richard Lugar, who wanted more steps taken to avoid conflicts of interests between Clinton's new job and the charitable foundation of her husband, former president Bill Clinton.