President Barack Obama on Monday delivered a major speech on the administration policy toward Libya, claiming the U.S. military intervention was to avoid civilian casualties in the North African country instead of "regime change".

U.S. President Barack Obama speaks about Libya at the National Defense University in Washington, Monday, March 28, 2011. (Xinhua/AFP Photo)

Facing mounting domestic and international criticism for his ambiguous military policy in Libya recently, Obama's speech was aimed at easing the criticism.

At present, how the military intervention will end remains unknowable at this stage, experts said, and critics fault Obama for not providing an outline of what comes next.

In his 27-minute speech delivered at National Defense University, Obama defended U.S. involvement in Libya, saying the intervention was to safeguard "interests and values" of the United States.

"When our interests and values are at stake, we have a responsibility to act. That is what happened in Libya over the course of these last six weeks," he said.

"The United States has worked with our international partners to mobilize a broad coalition, secure an international mandate to protect civilians, stop an advancing army, prevent a massacre, and establish a no-fly zone with our allies and partners," he said.

Meanwhile, Obama said broadenning the military mission in Libya to include "regime change" would be a mistake.

Invoking "sacrifices" the United States made in the war in Iraq, Obama said the country cannot afford to repeat it in Libya.

"The task that I assigned our forces -- to protect the Libyan people from immediate danger, and to establish a no-fly zone -- carries with it a UN mandate and international support," Obama said. If the administration "tried to overthrow Gaddafi by force, our coalition would splinter. We would likely have to put U.S. troops on the ground, or risk killing many civilians from the air.

NATO will take command over the entire Libya operation on Wednesday, but the country would continue to provide assistance to the coalition, Obama said.

He said the U.S. "will play a supporting role -- including intelligence, logistical support, search and rescue assistance, and capabilities to jam regime communications."

"Because of this transition to a broader, NATO-based coalition, the risk and cost of this operation -- to our military, and to American taxpayers -- will be reduced significantly," Obama added.

In addition to NATO responsibilities, the U.S. will work with the international community to provide assistance to the Libyan people, and will safeguard the more than 33 billion U.S. dollars of frozen Libyan assets, and will "make sure" the Libyan people receive it, Obama said.

VietNamNet/Xinhuanet