House Speaker John Boehner says "a line was crossed" that warrants the creation of a new select committee to investigate the Benghazi terrorist attacks when newly released documents showed "that the White House played a more significant role in the development of how they were going to describe" the violence that claimed four American lives on Sept. 11, 2012.

Four other committees in the House have probed the Benghazi attack, but with varying levels of coordination and success, Boehner said he believed it was finally time to create a cohesive investigation.

"It was time for us to bring this together into one place and to focus our efforts," Boehner, R-Ohio, told reporters at the Capitol today. "This is all about getting to the truth. This is not going to be a sideshow, it's not going to be a circus. This is a serious investigation."

House Democrats have promised to vote against the resolution to establish the select committee. While it will likely pass with Republican support, it remains unclear whether Minority Leader Nancy Pelosi will appoint anyone to the five slots Boehner has reserved for Democrats.

If Pelosi decides not to fill the positions, senior GOP aides say they believe Boehner could either appoint five Democrats himself, or choose five more Republicans to join the panel.

Boehner said he was further motivated to call on the House to establish the select committee when the State Department released documents that were previously withheld from the House Oversight Committee.

Last week, a new email from National Security Council communications adviser Ben Rhodes surfaced that coached then-U.S. Ambassador to the United Nations Susan Rice's round of interviews "to show that these protests were rooted in an Internet video, and not a broader failure of policy."

The video Rhodes referenced was an anti-Muslim YouTube video that sparked widespread protests across the Muslim world. The document also shows the White House advised Rice that the Benghazi attack was "spontaneously inspired" by protests at the U.S. embassy in Egypt that were motivated by an anti-Muslim video.

"Our system of government depends on transparency and accountability," Boehner said. "We owe it to the future of our country and to the next administration to do our job, to make it clear that the types of activities that may have gone on here are not acceptable in system of government."

Tension between House Republicans and the White House is near a breaking point as the House moves to establish the Benghazi select committee this week, and take votes on a resolution to find former IRS official Lois Lerner in contempt of Congress for refusing to testify at the House Oversight Committee and another measure calling on Attorney General Eric Holder to appoint a special counsel to investigate the IRS targeting scandal.

Boehner indicated that he expects the pressure mounting on the administration to be produce results.

"When is the administration going to tell the American people the truth? They've not told them the truth about Benghazi, they have not told the truth about the IRS, they've not told the truth about Fast and Furious," Boehner said. "Now, only one would have to guess, if they're not willing to tell the American people the truth, it must not be very pretty."

Nevertheless, the White House describes its efforts to cooperate with congressional oversight as "remarkable" even as President Obama works to implement recommendations from the Advisory Review Board, such as beefing up security at diplomatic posts throughout the world.

"We have not seen cooperation from Republicans in Congress on that effort," White House Deputy Press Secretary Josh Earnest told reporters today during a gaggle on Air Force One. "It's unfortunate that they seem more interested in these kinds of investigations than working with the administration to actually make sure that we're doing all that we can to keep our diplomats safe."