The U.S. asked a federal judge to lift an order temporarily blocking a Boeing-Lockheed Martin venture from buying Russian-made rocket engines for the Air Force, saying the purchases don’t violate sanctions imposed after Russia’s takeover of Crimea.

U.S. Court of Federal Claims Judge Susan Braden in Washington halted the sales until she receives assurances from the government that the transactions don’t run afoul of President Barack Obama’s March 16 sanctions against Russian Deputy Prime Minister Dmitry Rogozin, who heads the country’s defense and space industries.

The government request to lift the ban includes a letter from a senior Treasury Department lawyer stating that “to the best of our knowledge” purchases from rocket maker NPO Energomash, which is owned by the Russian government, “currently do not directly or indirectly contravene” the sanctions against Rogozin.

The State Department concurred with the Treasury finding and the Commerce Department deferred to the other agencies, according to the government’s filing late yesterday.

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Breaden’s order came as part of a lawsuit filed April 28 by billionaire Elon Musk’s Space Exploration Technologies The company accused the Air Force of illegally shutting it out of the military satellite-launch business by giving a monopoly to the Boeing-Lockheed venture, known as United Launch Alliance.

ULA also filed papers late yesterday asking the judge to lift the ban.

The SpaceX suit is a protest of the ULA contract. The company didn’t request a halt to the Russian rocket sales.

The case is Space Exploration Technologies Corp. v. U.S., 14-cv-00354, U.S. Court of Federal Claims (Washington).