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Nearly a month after the deadly attack on the U.S. Consulate in Libya, a House committee is set to hear testimony from an American security officer who claims that pleas for enhanced safety measures in the days leading up to the attack were rebuffed by higher-ups at the State Department.

An aide to the House Oversight and Government Reform Committee confirmed Monday that Lt. Col. Andy Wood has agreed to testify before the panel at Wednesday's hearing.

Wood, the former head of a Special Forces security team, has already said in interviews that security officials wanted "more, not less" security staffing but that his team was pulled from Tripoli before the attack. Wood's testimony Wednesday could serve to fill in the blanks for lawmakers wondering exactly what happened in the run-up to the Sept. 11 attack that left four Americans dead, including U.S. Ambassador Chris Stevens.

Lawmakers' questions of late have focused sharply on whether the State Department had let security slide in a violent and volatile region.

"My understanding is that there were requests made, and those requests were denied," Rep. Mike Rogers, R-Mich., chairman of the House Intelligence Committee, told Fox News.

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Also, Monday, Fox News learned that Sen. Bob Corker, R-Tenn., had just returned from a fact-finding mission to Libya. Corker is the second lawmaker to visit there in less than 24 hours.

Rep. Jason Chaffetz, R-Utah, was there over the weekend as part of the House probe into the attacks.

Chaffetz confirmed to Fox News that a security waiver had been signed by the State Department for the consulate, allowing it not to confirm with specific physical security requirements.

In an interview with CBS News, Wood said that when the State Department was asked for more security, they said: "You've got to do with less."

"For what reasons, I don't know," Wood said.

He said that when he learned his 16-member force was being pulled from Tripoli in August, there was "concern amongst the entire embassy staff."

A State Department official, though, said an earlier request made in February for the 16-member team to remain in Libya longer was granted. Further, the official claimed the department never received any request for a post-August extension. The official added the team was replaced without any reduction in personnel or loss of skill sets.

But Wood told CBS that the department was warned that ending the assignment and decreasing security was "just unbelievable" given how "dangerous" the region is.

An independent panel commissioned by the State Department, meanwhile, has launched its own investigation into the Libya strike. In addition, a source familiar told Fox News that White House counterterrorism adviser John Brennan is expected to be in Libya on Tuesday to check in on the broader investigation.

Wood's testimony, along with that of other officials Wednesday, could fuel concerns that the State Department may not have been prepared for the mounting security threat in eastern Libya.

"We know about our troops and how important it is to protect them and to be behind them, but we have so many people, like the State Department, that are out there, and in situations where maybe they're not as protected as well as they should, and we need to evaluate that," Rep. Dutch Ruppersberger, D-Md., top Democrat on the House Intelligence Committee.

Fox News' James Rosen and The Associated Press contributed to this report.