WASHINGTON — President Barack Obama assumed responsibility Tuesday over the deadly terror attack in Libya last month that killed four Americans just hours after Secretary of State Hillary Rodham Clinton sought to shoulder the blame for any mistakes the administration made. “She works for me,” the president said in New York in his second presidential debate with Republican challenger Mitt Romney. “I'm the president and I'm always responsible, and that's why nobody's more interested in finding out exactly what happened than I do.” With three weeks before the presidential election, the administration has been unable to put to rest its handling of the Benghazi attack that killed Ambassador Chris Stevens, a State Department computer specialist and two former Navy SEALs who were working as contract security guards. Obama's statement came amid a spirited back-and-forth with the former Massachusetts governor over the assault on the consulate, the only significant foreign policy disagreement in an hour-and-a-half exchange dominated by domestic concerns. Romney challenged the president to explain why US officials argued for more than a week after the Sept. 11 assault that it stemmed from a protest against a film produced in the US ridiculing Islam. “Whether there was some misleading, or instead whether we just didn't know what happened, you have to ask yourself why didn't we know,” Romney said. “It was very clear this was not a demonstration,” he said. “This was an attack by terrorists.” The two also traded jabs on how quickly the president declared Benghazi an act of terror — with Romney insisting it took two weeks and Obama saying he said as much the day after in an address from the White House Rose Garden. That drew an intervention from the moderator, CNN's Candy Crowley, who appeared to side with Obama. Before the debate, Clinton tried her best to defuse an issue that is threatening to become a potential obstacle to Obama's re-election campaign. In a statement that could have long-term ramifications given the persistent speculation that she might run for president in four years' time or stay in public life, Clinton accepted responsibility for the safety of the State Department's staff and diplomatic missions. It was quickly brushed aside by leading Republicans who directed their criticism toward the president. But her message left several lingering questions unanswered, such as whether the attack on the 11th anniversary of the Sept. 11, 2001, terrorist attacks occurred because of intelligence failures and why administration officials repeated for so long their account of the anti-American demonstration gone awry. “I take responsibility,” Clinton said, reiterating comments she made in a television interview late Monday. “I'm in charge of the State Department's 60,000-plus people all over the world (at) 275 posts.” Clinton's remarks may have been intentionally vague. Neither in her interviews or her statement does she spell out what exactly she assumes responsibility for, a tactic that may have been employed to avoid culpability for specific failings or tasks strictly outside her control. State Department spokeswoman Victoria Nuland said Clinton “was extremely clear what she takes responsibility for, which is the operation of this department, all of the men and women here.” — AP