House Republicans pushed ahead Monday with their investigation of the deadly assault on the U.S. diplomatic mission in Benghazi, Libya, as President Barack Obama asserted that GOP charges of a cover-up are baseless.

The latest Republican focus is the independent review that slammed the State Department for inadequate security at the installation before the twin nighttime attacks that killed Ambassador Chris Stevens and three other Americans on Sept. 11, 2012.

Rep. Darrell Issa, R-Calif., chairman of the House Oversight and Government Reform Committee, asked the two authors of the investigation — veteran diplomat Thomas Pickering and retired Adm. Mike Mullen, the former chairman of the Joint Chiefs of Staff — to meet privately with committee staff to answer questions about their review. Democrats countered that if Congress wants to talk to them, Issa should hold a full, open hearing.

Republicans contend that the Obama administration misled Congress and the American people in the immediate aftermath of the attack, trying to play down an act of terrorism that would reflect poorly on Obama weeks before the 2012 presidential election.

Emails disclosed Friday showed that State Department and other senior administration officials pushed for references to prior warnings and al-Qaida to be deleted from the talking points used by U.N. Ambassador Susan Rice five days after the attack. One email suggested there was concern that Congress could use those issues as ammunition against the State Department.

At a White House news conference, Obama dismissed the GOP focus on the talking points as a politically driven “sideshow,” pointing out that he said “act of terror” on Sept. 12 and the talking points assessment was similar to the daily presidential briefing he had received.

“There’s no there there,” Obama said. “The fact that this keeps on getting churned up, frankly, has a whole lot to do with political motivations.”

He added that the victims — four Americans, including Ambassador Chris Stevens — are dishonored “when we turn things like this into a political circus.”

He noted that Matt Olsen, director of the National Counterterrorism Center, told Congress that Benghazi was a terrorist attack with potential links to al-Qaida three days after Rice’s appearance on five Sunday talk shows.

“So if this was some effort on our part to try to downplay what had happened or tamp it down, that would be a pretty odd thing that three days later we end up putting out all the information that in fact has now served as the basis for everybody recognizing that this was a terrorist attack and that it may have included elements that were planned by extremists inside of Libya,” the president said. “Who executes some sort of cover-up or effort to tamp things down for three days?”

The emails comprising the inter-agency discussion on how to best describe the events in Benghazi were shared with Congress in February as a condition for allowing the nomination of John Brennan for CIA director to move forward.

The general counsel for the office of the Director of National Intelligence briefed members and staff from the Senate Intelligence panel and leadership on the emails Feb. 15 at a session in which staff could take notes. A similar briefing took place on March 19 for the House Intelligence panel and leadership staff, according to a senior administration official.

New details on the emails emerged last week. Obama argued that lawmakers had reviewed them several months ago but suddenly they were treated as fresh revelations.

Although the talking points were heavily edited, Rice still referred to al-Qaida and extremists when she appeared on the Sunday shows.

“It’s clear that there were extremist elements that joined and escalated the violence; whether they were al-Qaida affiliates, whether they were Libyan-based extremists or al-Qaida itself, I think, is one of the things we’ll have to determine,” she said.

Issa has argued that Congress needs to get the facts. He wants to hear from Pickering and Mullen about their investigation and he asked that they turn over documents, communications, lists of witnesses, notes and other material by Friday.

He pointed to the testimony of three State Department witnesses last week who criticized the Accountability Review Board’s work as incomplete and flawed.

“The White House and the State Department have touted the ARB’s report as the definitive account of how and why the Benghazi attacks occurred,” Issa said in separate letters to Pickering and Mullen. “It is necessary for the committee to understand whether the criticisms of the ARB’s work that we heard from witnesses on May 8, 2013 are valid.”

But the top Democrat on the committee, Rep. Elijah Cummings of Maryland, told Issa that he should bypass private depositions from the two men and go directly to an open hearing on May 22. Issa told Pickering and Mullen that they would work out a hearing for their public testimony at a later date.