A Senate committee on Thursday is scheduled to convene the first congressional hearing on the shootings at the U.S. Army base at Ft. Hood, Texas, in which a U.S. Army Major, Nidal Malik Hasan, is alleged to have killed 12 fellow soldiers and one civilian. 

Joseph Lieberman, an Independent senator from Connecticut who heads the Senate Committee on Homeland Security and Government Affairs, says Congress cannot wait for inquiries being conducted by the Pentagon and Department of Justice.

Confirming that he intends to proceed with the hearing, Lieberman said while he supports current investigations, he considers the Ft. Hood shootings an act of terrorism and Congress has an obligation to carry out its own inquiry.

"Our committee in both its traditional governmental oversight jurisdiction and its more recent homeland security jurisdiction, has an important responsibility under the rules of the Senate to determine whether the federal government could have prevented the murders at Ft. Hood," Lieberman said.

The remarks came as Lieberman and ranking Republican on the committee, Susan Collins of Maine, continued consultations with key officials, including Defense Secretary Robert Gates, U.S. Attorney General Eric Holder, FBI Director Robert Mueller and Army Secretary John McHugh, himself a former member of Congress.

The Obama administration had earlier made known its preference that congressional inquiries should wait until the conclusion of federal investigations into the shootings.

Republican lawmakers in the House of Representatives strongly disagree with this, saying Congress has a responsibility to press ahead with a full investigation.

Pete Hoekstra, the ranking Republican on the House Permanent Select Committee on Intelligence, asserted to reporters on Tuesday that the Ft. Hood shootings resulted from what he called a systemic breakdown with important implications for U.S. security.

"This is a systemic problem.  We believe that this jeopardizes, in the future, our national security," Hoekstra said. "And all of it revolves around the threat of radicalization of Americans in our homeland."

Lawmakers on both sides of the political aisle are focused on the question of whether, similar to the September 11, 2001 al-Qaida attacks on the U.S., military and government officials may have failed to act on information on hand.

Republican Senator Susan Collins says "Was this once again a failure to connect the dots?  Were there inexcusable gaps and communications failures and failures to act on compelling evidence that might have allowed us to prevent the attack at Ft. Hood?"

President Barack Obama has set an end-of-month deadline for receiving a government report.

Opening a hearing on Wednesday with Attorney General Holder, the Chairman  of the Senate Judiciary Committee, Vermont Democrat Patrick Leahy, said Congress must conduct responsible oversight, but should not interfere with the military's investigation.

"We should and we will conduct responsible oversight [but] try not to do it in a reckless fashion because we should not take steps that are going to interfere with the ongoing investigation or stand in the way of military prosecutors," Leahy said. "I want them to be able to compile a thorough and complete case."

No military or FBI officials are expected to attend Thursday's Senate Homeland Security hearing, although technically committee chairmen retain the power to issue subpoenas to compel officials to testify.

Army major Hasan has been charged with 13 counts of murder in the incident at Ft. Hood on November 5.