Washington - President Barack Obama said Wednesday night that waterboarding authorized by former President George W. Bush was torture, and the information gained from terror suspects through its use could have been obtained by other means. "In some cases it may be harder," he conceded at a White House news conference marking a whirlwind first 100 days in office.

    Obama also expressed optimism that Chrysler could remain a "going concern," possibly without filing for bankruptcy. He said "unions and creditors have come up with a set of potential concessions that they can live with," adding, "All that promises the possibility that you can get a Chrysler-Fiat merger."

    The prime-time news conference was the third of Obama's presidency, and the first not dominated by the economy that has thrown millions of Americans out of work.

    At a town-hall style meeting in Missouri earlier in the day, as well as in the White House East Room, Obama said progress has been made in rebuilding the economy, yet more remains.

    "And all of this means you can expect an unrelenting, unyielding effort from this administration to strengthen our prosperity and our security - in the second hundred days, and the third hundred days, and all the days after."

    He called on Congress to enact his ambitious agenda, including health care legislation, a new energy policy and steps to impose new regulations on the financial industry to prevent a recurrence of the collapse that recently brought the economy to its knees.

    Obama also said he was "absolutely convinced" he had acted correctly in banning waterboarding, an interrogation technique that simulates drowning, and approved making public the Bush administration memos detailing its use as well as other harsh methods used on terrorist suspects. "Not because there might not have been information that was yielded by these various detainees ... but because we could have gotten this information in other ways, in ways that were consistent with our values, in ways that were consistent with who we are."

    Obama has come under heavy criticism from former Vice President Dick Cheney and other Republicans for his actions, who have questioned whether they have rendered the country less safe.

    Cheney as well as some congressional Republicans have urged Obama to release memos they say will show waterboarding was successful in obtaining information. But the president, in a White House exchange with House Republican leader John Boehner last week, said the record was equivocal.

    Obama told reporters he has read the documents Cheney and others are referring to.

    The news conference lasted an hour and covered topics ranging from the outbreak of swine flu - which Obama referred to as the H1N1 virus, evidently in deference to U.S. pork producers - to abortion and the recent flare-up in violence in Iraq.

    He gave assurance that one way or another Pakistan's nuclear aresanl would not fall into the hands of Islamic extremists. He said he was confident that Pakistan would handle the issue on its own but he left the door open to the U.S. taking action to secure the weapons if need be.

    On the auto industry, he was notably more upbeat about Chrysler's prospects for survival than an administration report issued nearly a month ago.

    "I'm feeling more optimistic," he said.

    Obama did not say so, but Italian automaker Fiat Group SpA is expected to sign a partnership agreement with Chrysler LLC by Thursday as part of negotiations to keep the struggling U.S. automaker alive without bankrupcty protection.

    The administration has given General Motors Corp. an additional month to present a restructuring plan that meets his administraiton's approval.

    "They're still in the process of presenting us with another plan," he said.

    He added, "I would love to get the U.S. government out of the auto business as soon as possible."

    On a political matter, Obama said he thought that Pennsylvania Sen. Arlen Specter's switch Tuesday from Republican to Democrat would "liberate him to cooperate on critical issues like health care, like infrastructure and job creation, areas where his inclinations were to work with us but he was feeling pressure not to."

    Specter gave majority Democrats 59 votes in the Senate, pushing them one step closer to the 60 needed to overcome Republican filibusters. But Obama said he did not expect a rubber stamp Senate, an acknowlegement that his ambitious legislative agenda poses challenges.