NASA and the United Launch Alliance (ULA) responded today to statements by Russian Deputy Prime Minister Dmitry Rogozin that would affect ULA’s use of Russian RD-180 rocket engines and could affect Russia’s participation in the International Space Station (ISS) after 2020.

As part of the ongoing tense relationship between the United States and Russia because of the Ukraine situation, Rogozin said today via tweets and a story in the Russian media that Russian rocket engines no longer may be used for launching U.S. military satellites; Russia will conduct a cost-benefit analysis of its use of the ISS before deciding whether to continue operations past 2020 (NASA announced in January that it will continue operations through 2024 and clearly had been expecting Russia, at least, to agree); and it will consider terminating the operations of 11 ground stations located in Russia for the U.S. GPS navigation satellite system if the United States does not reciprocate by allowing GLONASS ground stations on U.S. soil.

NASA and ULA each issued statements saying they had received no official notification from the Russian government affecting their activities.

NASA’s statement in full is as follows:

“Space cooperation has been a hallmark of US-Russia relations, including during the height of the Cold War, and most notably, in the past 13 consecutive years of continuous human presence on board the International Space Station. Ongoing operations on the ISS continue on a normal basis with a planned return of crew tonight (at 9:58 p.m. EDT) and expected launch of a new crew in the next few weeks. We have not received any official notification from the Government of Russia on any changes in our space cooperation at this point.”

ULA’s statement in full is as follows:

“ULA and our NPO Energomash supplier in Russia are not aware of any restrictions. However, if recent news reports are accurate, it affirms that SpaceX’s irresponsible actions have created unnecessary distractions, threatened U.S. military satellite operations, and undermined our future relationship with the International Space Station.

“We are hopeful that our two nations will engage in productive conversations over the coming months that will resolve the matter quickly.

“ULA and our Department of Defense customers have always prepared contingency plans in the event of a supply disruption. ULA has two launch vehicles that can support all of customers’ needs. We also maintain a two-year inventory of engines to enable a smooth transition to our other rocket, Delta, which has all U.S.-produced rocket engines.”

ULA’s complaint about SpaceX is a reference to a lawsuit filed by SpaceX against the U.S. government for awarding a contract to ULA on a sole source basis rather than competing it. As part of the lawsuit, SpaceX discussed the fact that Rogozin oversees Russia’s space sector and is subject to U.S. sanctions, leading a judge in the U.S. Court of Federal Claims to issue an injunction against payments to Russia for RD-180 engines used by ULA for the Atlas V rocket, an injunction that was lifted last week.