WASHINGTON, Jan. 23 (Xinhua) -- U.S. President George W. Bush, trying to seek advantage in the debate on a controversial domestic spying program, said Monday that the program is legal and vital in the war against terror.

    In his fourth public speech on national security in six weeks, Bush told a full coliseum of 9,000 audience at Kansas State University that the program, authorized by him in 2002 to spy on telephone calls and emails between United States and overseas without court warrants, is within the framework of the law and he has congressional authorization on the issue.

    He said the government only intercepted communications including a "known al Qaeda suspect."

    "In other words, we have ways to determine whether or not someone can be an al Qaeda affiliate or al Qaeda. And if they're making a phone call in the United States, it seems like to me we want to know why," he said.

    Many U.S. law experts and the congressional research arm have pointed out that the program violated a law known as the Foreign Intelligence Surveillance Act, which requires court warrant for spying on a U.S. citizen.

    The U.S. Senate Judiciary Committee will open hearings on the issue next month.

    Defending his position, Bush argued that his legality on the issue came from the fact that the U.S. Congress authorized him to have sweeping power in anti-terror efforts after the Sept. 11 terror attacks in 2001.

    "Congress gave me the authority to use necessary force to protect the American people, but it didn't prescribe the tactics,"he said.

    "One of the ways to protect the American people is to understand the intentions of the enemy ... If they're making phone calls into the United States, we need to know why to protect you,"said Bush.

    The speech is part of the Bush administration's new intensive public relations effort to win support for the program.

    White House advisors have reportedly decided to turn the spying debate into a political asset rather than a liability, hoping to use it to attack Democrats and re-establish Bush's position after a difficult year.

    So far there is no evidence that such tactics really work. In a recent AP-Ipsos survey, a majority of Americans (56 percent), said Bush should be required to get a warrant before monitoring electronic communications between American citizens and suspected terrorists. Enditem