BERLIN (AP) - NASA's leader has dismissed concerns that U.S. friction with Russia might spell the end of the International Space Station, saying it could keep operating without Russia.
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 said Monday that the space station is run jointly by the U.S., 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."
Bolden says NASA expects private companies to start transporting astronauts to the space station by 2017.