WASHINGTON — When President Trump met with top Russian officials in the Oval Office on Wednesday, White House officials barred reporters from witnessing the moment. They apparently preferred to block coverage of the awkwardly timed visit as questions swirled about whether the president had dismissed his F.B.I. director in part to squelch the investigation into possible ties between his campaign and Moscow.

But the Russians, who have a largely state-run media, brought their own press contingent in the form of an official photographer. They quickly filled the vacuum with their own pictures of the meeting with Mr. Trump, Sergey V. Lavrov, the Russian foreign minister, and Sergey I. Kislyak, Moscow’s ambassador to the United States.

Within minutes of the meeting, the Foreign Ministry had posted photographs on Twitter of Mr. Trump and Mr. Lavrov smiling and shaking hands. The Russian embassy posted images of the president grinning and gripping hands with the ambassador. Tass, Russia’s official news agency, released more photographs of the three men laughing together in the Oval Office.

The White House released nothing.

The result was a public relations coup of sorts for Russia and Mr. Lavrov in particular, who not only received a collegial Oval Office welcome from the president, but the photographic evidence to prove it. By contrast, when Secretary of State Rex W. Tillerson traveled to Moscow last month, President Vladimir V. Putin of Russia kept him waiting for hours before granting him an audience at the Kremlin. Then, too, Mr. Tillerson left his American press contingent behind.

Mr. Kislyak has figured prominently in the furor surrounding the Trump team’s contacts with Moscow. It was conversations between the ambassador and Michael T. Flynn, the president’s former national security adviser, that ultimately led to Mr. Flynn’s ouster in February, ostensibly because he had lied to Vice President Mike Pence about whether the two had discussed United States sanctions on Russia. The White House had not divulged that Mr. Kislyak was to be present at Wednesday’s meeting.

Mr. Trump’s session with Mr. Lavrov was listed on his schedule as “Closed Press,” meaning the news media would not have a chance to photograph or otherwise document the meeting. “Our official photographer and their official photographer were present — that’s it,” a White House aide said, speaking on condition of anonymity, lacking authorization to describe the ground rules.

The difference, of course, is that while official White House photographers have broad access to the president, their presence is not considered a substitute for that of independent news media, which routinely request and secure access to official presidential movements and meetings so they can obtain their own images and produce their own reports. In Russia, where the independent news media are severely limited, there is no such regular press access to government officials apart from state-controlled organizations.

On Wednesday morning, when the American press pool was assembled unexpectedly in the West Wing, reporters thought that White House officials might have reconsidered and decided to allow a glimpse of Mr. Trump’s meeting with the Russians after all. But instead, they were allowed into the Oval Office for a few moments to cover another, previously undisclosed meeting: between Mr. Trump and Henry Kissinger, the Nixon administration’s secretary of state.

Former White House officials were left to wonder about the security implications of having allowed a Russian photographer unfettered access to the American president’s office.

Colin H. Kahl, the former national security adviser to Vice President Joseph R. Biden Jr., took to Twitter to pose what he called a “deadly serious” question: “Was it a good idea to let a Russian gov photographer & all their equipment into the Oval Office?”

David S. Cohen, the former deputy director of the C.I.A. during the Obama administration, responded: “No, it was not.”