U.S. President George W. Bush personally inspected the ultra-secret National Security Agency ( NSA) on Wednesday, a move aimed to defend a controversial domestic spying program authorized by him.

During the tour, Bush said the program, in which the NSA monitors the international communications of U.S. residents without court warrants, is very necessary and vital, because "we must learn the intentions of the enemies before they strike."

The president's rare trip to the heavily secured site of the super-secret spy agency in suburban Maryland was also aimed to boost the morale of the people carrying out the work of the spying program.

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 (FISA), which requires court warrant for spying on a U.S. citizen.

The U.S. Senate Judiciary Committee will open hearings on the issue in two weeks.

However, during his visit to the NSA, Bush again pledged to continue to reauthorize the program as long as a threat exists, and urged Americans not to be lulled into thinking that the threat from terrorism is over because there has not been an attack on U.S. soil since the Sept. 11 attacks in 2001.

"We must be able to quickly detect when someone linked to al- Qaida is communicating with someone inside of America," he said.

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

On Monday, he delivered a speech in Kansas State University, reasserting that he has the legal power to keep the spying program going without court warrants.

Recently, 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.

Source: Xinhua