The Senate Armed Services Committee postponed its Monday briefing on the deadly Fort Hood massacre at the behest of the White House, despite calls from some lawmakers to press forward with a congressional investigation into the shooting rampage that killed 13 and wounded 29.
An aide to committee chairman Sen. Carl Levin, D-Mich., told Fox News that the meeting is delayed "at the request of the administration." Army Secretary John McHugh and Army Chief of Staff Gen George Casey were to have briefed committee members privately on the shooting.
Army psychiatrist Maj. Nidal Malik Hasan was charged on Thursday with the deadly shooting spree. Army investigators have said Hasan is the only suspect and could face additional charges.
Obama already had ordered a review of all intelligence related to Hasan and whether the information was properly shared and acted upon within government agencies. Several members of Congress, particularly Rep. Peter Hoekstra, the top Republican on the House Intelligence Committee, have also called for a full examination of what agencies knew about Hasan's contacts with a radical Muslim cleric in Yemen and others of concern to the U.S.
Hoekstra confirmed this week that government officials knew of about 10 to 20 e-mails between Hasan and Anwar al-Aulaqi, beginning in December 2008.
A joint terrorism task force overseen by the FBI learned late last year of Hasan's repeated contact with the cleric, who encouraged Muslims to kill U.S. troops in Iraq. The FBI said the task force did not refer early information about Hasan to superiors because it concluded he wasn't linked to terrorism.
Department of Defense spokesman Gary Comerford declined to confirm Monday whether the department is conducting its own investigation, referring Fox News to speak with the department's head of public affairs.
In a video and Internet address released by the White House on Saturday, President Obama urged Congress to hold off on any investigation of the Fort Hood rampage until federal law enforcement and military authorities have completed their probes into the shootings.
While on an eight-day trip to Asia, Obama called on lawmakers to "resist the temptation to turn this tragic event into the political theater."
"The stakes are far too high," he said. "There is an ongoing investigation into this terrible tragedy. That investigation will look at the motives of the alleged gunman, including his views and contacts.
"We must compile every piece of information that was known about the gunman, and we must learn what was done with that information. Once we have those facts, we must act upon them," he added.
Defense Secretary Robert Gates, speaking to reporters aboard his plane last week, said all those privy to details on the ongoing investigation into the shooting "should just shut up."
But Sen. Joe Lieberman, ID-Conn., chairman of the Homeland Security and Governmental Affairs Committee, said he will proceed with his committee's investigation into the shooting, saying Obama did not indicate on Saturday that it should push back Thursday's scheduled testimony.
"We saw nothing in the president's transcript from Saturday that asked Congress to hold back," an aide speaking on condition of anonymity told Fox News.
"We very much agree with President Obama's sentiments that the full story behind the murderous act at Fort Hood must be told," Lieberman along with Maine Sen. Susan Collins, the ranking Republican on the committee, said in a joint statement over the weekend. "Our goal, and the purpose of this inquiry, is to make as certain as possible that no such attack ever occurs again on an American military base. We will focus on national and homeland security and will not compromise the criminal case being conducted by law enforcement."
Fox News' Trish Turner and Justin Fishel and the Associated Press contributed to this report.