The head of Russian space agency Roscosmos said on Thursday he wanted NASA to explain why it had abruptly canceled his planned visit to the United States, blaming the move on political infighting in Washington.
Dmitry Rogozin, who is under U.S. sanctions, was scheduled to visit next month at NASA's invitation. But NASA administrator Jim Bridenstine told The Washington Post last week that the invitation had been rescinded at the request of U.S. senators.
"It's a disgrace, this is illegal, and complete international lawlessness," Rogozin told the Rossiya-24 state TV channel.
Several U.S. senators were reported to be deeply unhappy about the prospect of Rogozin being allowed to visit the United States despite his being on a sanctions list over his support for his country's 2014 annexation of Ukraine's Crimea region.
Rogozin said NASA appeared to have fallen victim to a conflict between Congress and President Donald Trump. Pro-Kremlin politicians often say that they believe Trump is seeking to improve relations with Moscow, but is being held back by anti-Russian lawmakers.
"I think that America is now consumed by what is essentially its second civil war," Rogozin said, commenting on why his visit had been canceled.
"(What happened) ... is a piece of the battle between Congress and Trump, and NASA in this particular case is a victim of this battle.
"We are waiting for our colleagues to calm down. We are waiting for an explanation."
Despite the snub, Rogozin said he remained open to cooperation with the United States in the sphere of space and invited NASA's Bridenstine to come to Russia for talks on how the two agencies could work together in future, something he said both countries needed.