The summer of disappearing White House press briefings Trump spokeswoman Sarah Sanders spent just 4 hours at the podium in summer 2018.

It's been the summer of the disappearing White House press briefing.

President Trump’s press secretary Sarah Sanders fielded reporters’ questions in the James S. Brady press briefing room just 13 times during all of June, July and August. An ABC News analysis found Sanders spent a combined three hours and 58 minutes behind the podium.

All told, Sanders held fewer briefings and spent less time in the briefing room this summer than during the same period in 2017 and the comparable summer months each year of the last two presidencies.

And this when swirling headlines generated even more questions than usual -- and critics say demanded more accountability as well.

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Obama press secretary Josh Earnest and deputy press secretary Eric Schultz held 35 on-camera press briefings in the summer of 2016, totaling about 39 hours of time taking formal questions, by ABC’s analysis.

In the summer of 2008, the final year of the George W. Bush administration, spokespersons Dana Perino, Tony Fratto and Gordon Johndroe held 32 on-camera briefings, according to public records, including many from Texas where President Bush vacationed at his Crawford ranch. All told, they took questions for a combined nine hours and 24 minutes in formal briefings over three months.

On-camera press briefings, which became routine starting in the 1990s, have offered Americans an opportunity to regularly see and hear from top White House officials on a variety of important domestic and international topics. They have also allowed journalists to hold the executive accountable by asking questions in public view.

When asked about the lack of press briefings, White House officials frequently point to the fact that the president himself often takes questions during photo sprays and other functions in the West Wing.

“President Trump directly engages and is more accessible to the press than any president before him,” Sanders said.

On some occasions, White House staff have explained the absence or cancellation of a formal press briefing citing the president’s schedule – invoking a time conflict with other official functions or out-of-town travel.

“We are available every day to answer questions from members of the media - we often do that through in-person meetings, on-camera interviews, email, phone calls and press briefings,” Sanders said.

There has not been an opportunity to question Sanders publicly in more than nine days.

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U.S. relations with Russia and the special counsel’s investigation of Russian interference in the 2016 election have dominated the topics discussed over the just four hours of questioning at formal White House briefings in June, July and August 2018.

The same period saw significant developments with North Korea; Iran; trade negotiations with China, Canada, Mexico and the E.U.; appointment of Supreme Court nominee Brett Kavanaugh; mass shootings, separation of immigrant families along the U.S.-Mexico border; and ongoing military operations in Afghanistan and Iraq, among other issues. Reporters often raised these subjects but were afforded limited time for questions.

Five briefings were held in June, three in July and five in August. The average length was 23 minutes.

With President Trump traveling to Charlotte, N.C., on Friday, there was no formal White House press briefing scheduled -- and it's unclear when the next briefing will be held.

Senior White House officials say the president plans to spend a record 40 days of official travel up to the Nov. 6 midterm elections, a pace which could mean just a handful of formal White House press briefings between now and then.

ABC News' Devin Dwyer contributed reporting.