Russian President Vladimir Putin holds the first meeting of the Council for Strategic Development and Priority Projects at the Kremlin in Moscow on July 13, 2016. / AFP PHOTO / Sputnik / Michael Klimentyev/AFP/Getty Images (Michael Klimentyev/AFP/Getty Images)

In the latest in a series of tit-for-tat diplomatic skirmishes with the United States, Russia this week denied entry to the chairman of the U.S. Broadcasting Board of Governors and expelled him after several hours of detention at the Moscow airport.

The expulsion, on Tuesday night, came as Secretary of State John F. Kerry prepares to meet there Thursday with President Vladi­mir Putin on a U.S. proposal to coordinate counterterrorism operations in Syria.

The Russian Foreign Ministry, which gave BBG Chairman Jeff Shell no explanation at the time, later said he was on a still-secret list of names assembled by Russia to retaliate for U.S. sanctions against Russian politicians, businessmen and media figures imposed over Putin’s policies in Ukraine.

Shell is a presidential appointee to the board, whose members are unpaid. The BBG oversees government media outlets broadcasting overseas, including the Voice of America, Radio Free Europe and Radio Liberty.

He also serves as vice chairman of NBCUniversal, and was traveling to Russia on a trip arranged and paid for by that company, according to the BBG, although he also planned to attend a Radio Free Europe reception in Moscow.

The board statement said that Shell was “detained in a locked room for several hours, before being accompanied by Russian security officials to board a flight to Amsterdam. No explanation has yet been given,” it said. Shell, it said, was told he was subject to a “life-time ban” against visiting Russia.

Uncertainty about the “capacity” in which Shell was traveling also led the State Department to decline to answer questions about his detention. Privacy regulations prohibit releasing information about the circumstances of private U.S. citizens unless a waiver is filed. Shell was unavailable for comment.

“We are aware of this situation, and our embassy in Moscow assisted on the ground [Tuesday] night,” said Elizabeth Trudeau, State Department director of press operations. “Our embassy has spoken with the Russian government and is seeking further clarification on this issue.”

The BBG statement said that board officials “met with U.S. Ambassador John Tefft in Moscow this morning to discuss the incident and to thank the ambassador and the U.S. Department of State for their urgent attention to the matter.”

Russia has accused U.S. government broadcasters of spreading anti-Russian propaganda, particularly after its 2014 annexation of Crimea and about the conflict in eastern Ukraine between government forces and pro-Moscow separatists.

The United States and Europe have banned prominent individuals said to have played a role in the Crimean annexation, many of them seen as part of Putin’s inner circle. The European Union has also banned Dmitry Kiselyov, a firebrand television pundit who assails the West weekly on his Sunday night show.

“Their sense is that, okay, so you’re targeting our propaganda? We’re going to target yours,” said Leon Aron, a Russian-born scholar of Russia at the American Enterprise Institute who is also a member of the broadcasting board. “They have zero understanding that Jeff Schell and myself and others, we’re not even getting paid for any of this. It’s a supervisory, honorary, voluntary position.”

The United States and its European allies have expressed growing concern about Russian-language broadcasting in Eastern Europe, particularly in the Baltic states — former Soviet Union republics with major Russian-speaking populations. The states themselves — NATO-members Latvia, Lithuania and Estonia — have asked for increased alliance protection from provocative Russian behavior and a military buildup along Russia’s border with the Baltic states and Poland. At its summit last week in Warsaw, NATO announced additional deployments of about 4,000 troops to the area.

The increasing tensions have been reflected across a range of Russia’s relations with the West. Shell’s expulsion comes follows several recent diplomatic incidents between the United States and Russia, beginning early last month, when an official at the U.S. Embassy in Moscow was assaulted by a Russian security guard outside the facility. In response, the United States expelled two Russian diplomats. Russia responded by expelling two U.S. diplomats.

“The principle of tit-for-tat is deeply encoded in Russian diplomatic practice,” said Russia expert Andrew Weiss of the Washington-based Carnegie Endowment for International Peace. In Shell’s case, he said, “The United States and the European Union sanctioned officials of the Russian state-controlled media apparatus,” and the Russians put what they considered similarly-situated individuals “on their list.”

The Russians did not indicate whether Shell was listed as a BBG official, an NBC official, or both. “I assume that NBC, like any media company . . . has a Russian element to its business,” Weiss said. “The Russians are going to try to penalize him as a way of showing that you can’t put Russians on the sanctions list without consequences.”

Asked for more details on Shell’s detention, State Department deputy spokesman Mark Toner cited privacy concerns but said, “It’s not for us to explain what happened to [Shell]. . . . That’s really something for the Russians to speak to. . . . We’re still trying to sort through the precise details of what happened.”

Roth reported from Moscow.