The Twitter Inc. accounts of U.S. President Donald Trump, @POTUS and @realDoanldTrump, are seen on an Apple Inc. iPhone arranged for a photograph in Washington, D.C. Andrew Harrer | Bloomberg | Getty Images

The dog days of summer have taken their toll on the White House press briefing schedule. Presidential politics saturated the news in September, from a tell-all book depicting Donald Trump's White House as chaotic to controversy over Supreme Court nominee Brett Kavanaugh. But amid the steady volley of bombshell stories, the Trump administration all but abandoned one of the top tools in its arsenal to assert its own views: regular briefings from White House press secretary Sarah Huckabee Sanders. There was only one such briefing in all of September. When asked for a reason briefings have nearly disappeared, Sanders referred CNBC to comments she made earlier this week on "Fox News Sunday." "I always think if you can hear directly from the president, and the press has a chance to ask the president of the United States questions directly, that's infinitely better than talking to me," she said on the program. "We try to do that a lot, and you've seen us do that a lot over the last three weeks, and that's going to take the place of a press briefing when you can talk to the president of the United States."

Since he took office, Trump has proudly bucked the traditions of political messaging established by his predecessors. Yet as the turmoil surrounding his administration has intensified, Trump has further eclipsed his own communications team, stoking concerns as he takes on more and more of their responsibilities.

Press briefings plummet

White House press briefings, which usually involve Sanders answering questions from reporters packed into the James S. Brady Briefing Room, have grown scarce during Trump's second year in office. Last month's briefing slate was the lightest of any month in Trump's presidency, according to Politico. In her sole September briefing, Sanders took questions for about 18 minutes, ceding much of the roughly 40-minute session to Kevin Hassett, chairman of the Council of Economic Advisors. The light September briefing schedule culminated a trend that has steadily intensified throughout 2018. Sanders led press briefings at the Brady room podium at least 11 times in January, according to documents compiled by The American Presidency Project. With just two exceptions, there have been successively fewer briefings every month afterward. The Trump administration has devoted about half as much time to on-the-record press briefings as Barack Obama's White House had at the same point in his first term, Bloomberg reported in August. Hours after this story was published Tuesday morning, Sanders announced that she would field reporters' questions in an on-camera briefing — her first in 23 days. At that briefing, Sanders, joined by national security advisor John Bolton and Small Business Adminsitration chief Linda McMahon, answered questions for about 17 minutes. She defended Trump from the podium, saying the president was simply "stating facts" when he derisively imitated a woman's testimony against Kavanaugh last week. She also responded to a bombshell New York Times report on the Trump family's tax practices, calling the lengthy investigation "highly defamatory."

Trump takes the helm

The void once occupied by Trump's press team is, in fact, being filled — by the president himself. Trump has been a prolific Twitter user since long before he announced his campaign for the presidency. He had used the social media platform for everything from promoting his sundry brands and properties to proliferating the "birther" conspiracy theory that Obama was born outside the U.S. His habit continued after he moved into the White House. In his first year as president starting on Jan. 20, 2017, Trump sent an average of about seven tweets per day, according to data from trumptwitterarchive.com reviewed by CNBC. This year, Trump's daily average has increased to more than nine tweets per day, the data show. Even in public remarks, Trump has become more visible as his press team has receded. Last month, Trump appeared to be warming to the solo press conference, a format he had avoided almost entirely as president until recently. In the first 18 months of his presidency, Trump led just four solo press conferences, according to a study from Martha Joynt Kumar, an emeritus political science professor at Towson University. That's a smaller number than each of the five presidents before him — far fewer than the 15 solo pressers Obama gave in the same amount of time, though only slightly below George W. Bush's six solo press conferences. In late September, however, Trump took questions from reporters for well over an hour at the United Nations, addressing thorny issues such as the allegations hanging over Supreme Court nominee Brett Kavanaugh. On Monday, Trump addressed reporters for 30 minutes after touting the agreement struck with Canada as part of a deal to replace the North American Free Trade Agreement. In other areas, Trump has been more media-friendly than past presidents. Trump participated in 227 short question-and-answer sessions in his first year and a half — more than either Obama or Bush, according to Kumar's study. Trump also gave the second-highest number of interviews in that time of any president since Ronald Reagan.

'Holding them to account'