WASHINGTON – Under mounting pressure from Capitol Hill, NASA Administrator Jim Bridenstine withdrew an invitation to his Russian counterpart, a former deputy prime minister sanctioned by the U.S. government for his role in Moscow's annexation of Crimea from Ukraine in 2014.

“We had heard from numerous senators suggesting that this was not a good idea, and I wanted to be accommodating to the interest of the senators, so I have rescinded the invitation for Dmitry Rogozin to visit the U.S.," Bridenstine told The Washington Post late Friday. "However we will continue our strong working relationship with Russia as it relates to the International Space Station and sending our astronauts into space.”

Critics of the invitation included Sen. Mark Warner, D-Va., and New Hampshire Sen. Jeanne Shaheen, the top Democrat on the Senate Appropriations subcommittee, which funds NASA.

“America’s message to the Kremlin should be unequivocal: Actions have consequences,” Shaheen said last week. "Administrator Bridenstine’s invitation to Dmitry Rogozin, one of the leading architects of the Kremlin’s campaign of aggression towards its neighbors, undercuts our message and undermines the United States’ core national security objectives."

A former Oklahoma GOP congressman confirmed by the Senate last year, Bridenstine invited Rogozin to NASA's Johnson Space Center in Houston. There had been discussions about having Rogozin speak at nearby Rice University.

Rogozin is one of scores of Russians sanctioned by the Obama administration for involvement in the Crimean annexation. The sanctions included a ban on travel to the USA and a freeze on some assets held in U.S. banks.

Bridenstine's invitation to Rogozin was coordinated in advance, and a waiver allowing Rogozin to visit the USA was granted by the Treasury Department in June, according to NASA.

The NASA administrator formally extended the invitation to Rogozin during a visit to Russia in October to witness the launch of a Soyuz rocket carrying astronaut Nick Hague and Russian cosmonaut Alexey Ovchinin to the International Space Station. The launch failed on Oct. 11, triggering an emergency landing. Both men escaped unharmed.

Even amid growing tensions between Moscow and Washington, NASA and Roscosmos have maintained a cooperative alliance. Ever since NASA mothballed its space shuttle program in 2011, the United States has relied on Russia to transport astronauts to the ISS at a price that exceeds $80 million per seat.

The orbiting lab itself is a product of international cooperation, including from Russia. For more than 18 years, U.S. and Russian crews have maintained a permanent human presence on the station.

During his visit to Russia last fall, Bridenstine called the space station "a marvel of cooperation."

It's been a tradition that the heads of both space agencies visit each other's facilities. That didn't seem to be a problem until Rogozin was named to head Russia's space program and he needed special permission to visit the USA.

Rogozin is a nationalist who's made combative statements. After the imposition of sanctions in 2014, he suggested on Twitter that NASA could use trampolines to get to the space station instead of the Russian rockets.

Vladimir Kara-Murza, a prominent Russian dissident, opposed Washington's decision to grant Rogozin the waiver.

"Personal sanctions will work only if governments that operate them actually adhere to their terms," he wrote last year. "In rare cases, it may be justifiable to use 'national security waivers' to temporarily lift sanctions on certain individuals – and these justifications must be provided to the public and to Congress. It is doubtful, however, that inviting a notorious nationalist to lecture at Rice University constitutes reasonable grounds for such action."