Updated

The White House has been sitting on a preliminary review of the Fort Hood shooting since the end of November and refuses to share its contents with Congress, House Republicans say.

Republicans on the House Intelligence Committee have been pressing the Obama administration to either provide a copy of the review or brief them on it, arguing that it's important for relevant members to be in the loop as the review goes forward.

"They're stonewalling us. They won't give us anything," Rep. Mac Thornberry, R-Texas, told FoxNews.com. "They have just refused to brief Congress any further on this whole matter. ... It doesn't make sense to me."

The National Security Council last month took control over informational briefings on the Nov. 5 shooting rampage, which left 13 dead and dozens wounded at the Texas base. The preliminary report from intelligence agencies was due at the end of November.

A White House spokesman said in an e-mail Wednesday that the reason members of Congress have not been briefed on the report is because, "We're reviewing it."

But Thornberry said the White House is obligated to share the information it has. He cited the National Security Act of 1947.

He said he doesn't know whether the contents of the report have had any bearing on the administration's reluctance to part with it.

"I don't know if they don't like the information, (if it's) inconsistent with some sort of agenda or they're just trying to keep a real tight hold and control it completely," he said.

Debate has raged in Washington over whether law enforcement and intelligence circles missed obvious warning signs from Maj. Nidal Malik Hasan and over whether the attack should be considered an act of Islamic terrorism. A task force overseen by the FBI learned last year of Hasan's repeated contact with a radical cleric in Yemen.

Amid the furor, the White House has urged Congress to hold off on its own investigations until the proper authorities complete their reviews. President Obama in November asked lawmakers resist the urge to turn a "tragic event" into "political theater."

But Rep. Pete Hoekstra, R-Mich., ranking Republican on the intelligence committee, has led the charge to make sure lawmakers are at least in the loop.

In a Dec. 3 letter, he wrote Director of National Intelligence Dennis Blair complaining that he has not yet received a briefing even though the report has been handed in.

Hoekstra spokesman Jamal Ware said Blair has indicated his willingness to cooperate, but that the White House seems to be "blocking" the report.

"We don't know why," Ware said. "The goal here ultimately has to be preventing a recurrence of this."

Hasan was charged in the killings last month.

Fox News' Catherine Herridge contributed to this report.