"These revelations compel the House to take every possible action to ensure the American people have the truth about the terrorist attack on our consulate," top Republican Boehner said in a statement.
"In light of these new developments, the House will vote to establish a new select committee to investigate the attack, provide the necessary accountability, and ensure justice is finally served."
The move suggests Boehner finally relented to his party's right flank, which has long pressed for stronger action to probe the attack.
Seeking to elevate the investigation to a new level, the chief government watchdog in Congress slapped Secretary of State John Kerry with a subpoena compelling him to testify about Benghazi on May 21.
House Government Oversight Committee chairman Darrell Issa announced the subpoena in a tweet, saying "the State Department has failed to meet its legal obligations" to turn over all Benghazi-related documents.
Rules Committee chairman Pete Sessions, a close Boehner ally, said he would help establish the committee and hopes it will "force the administration to comply with the law, and provide answers for the American people."
- 'Hundred percent false' -
In the email three days after the September 11, 2012 assault, Obama's deputy national security advisor Ben Rhodes told Susan Rice -- at the time US envoy to the United Nations -- to blame the attack on local anger in Benghazi over an anti-Muslim Internet video.
It has since become clear that the attack was planned by armed militants.
Republicans have sought to expose administration obstruction in the aftermath of the attack, which occurred at the height of the 2012 US presidential race won by incumbent Obama.
On Thursday the White House dismissed the growing pressure, saying Republicans were seeking to "politicize a tragedy" and uncover a conspiracy "when they haven't been able to find one."
With Friday's special committee and subpoena announcements, exasperated State Department spokeswoman Marie Harf said Benghazi had already been investigated "ad nauseum, by multiple committees" and an internal Accountability Review Board.
Harf scoffed at the suggestion, put forward by Benghazi conspiracy theorist Senator Lindsey Graham, that the Rhodes email was a smoking gun in the administration's Benghazi account.
"It doesn't change the narrative" of what happened, Harf said of the email, adding that the administration had provided tens of thousands of documents to lawmakers on a rolling basis.
"I am confident that what the Republicans allege, that there was some attempt by this administration to cover up or spin what happened, is 100 percent false."