The Russian government last week said it wouldn't cooperate with America on the project beyond 2020. That warning followed the United States' imposition of sanctions on Russia over its actions in Ukraine.
NASA Administrator Charles Bolden today said that the space station is run jointly by the US, Russia, Japan, Europe and Canada, and no single partner could terminate the project.
Bolden told reporters in Berlin that, even if Russia withdrew, no participating nation "is indispensable on the International Space Station."
