NASA is suspending most of its cooperation with Russia as a result of the ongoing situation in Ukraine, agency officials announced Wednesday afternoon (April 2).

"Given Russia's ongoing violation of Ukraine's sovereignty and territorial integrity, NASA is suspending the majority of its ongoing engagements with the Russian Federation," officials said in a statement. "NASA and Roscosmos will, however, continue to work together to maintain safe and continuous operation of the International Space Station."

The news first broke Wednesday in the form of a leaked NASA memo posted online by spaceref.com. [Building the International Space Station (Photos)]

According to the memo, the agency is suspending all contacts with representatives of the Russian government, including email and teleconference communication, with the exception of activities necessary to keep the space station running smoothly. NASA officials can still attend "multilateral meetings" where Russian representatives are present outside of Russia, the memo states.

At the moment, Russia's Soyuz capsules are the only spacecraft that fly NASA astronauts to the International Space Station. NASA hopes to change that in the near future by using privately built U.S. spacecraft to ferry astronauts to and from the orbiting outpost.

Indeed, the statement stresses that NASA is committed to ending its dependence on Russia. It also asserts that American astronaut taxis would have been ready to begin operations in 2015 had NASA's commercial crew program been fully funded by Congress.

"With the reduced level of funding approved by Congress, we’re now looking at launching from U.S. soil in 2017," the official NASA statement reads. "The choice here is between fully funding the plan to bring space launches back to America or continuing to send millions of dollars to the Russians. It’s that simple. The Obama Administration chooses to invest in America — and we are hopeful that Congress will do the same."

NASA Administrator Charles Bolden has said that the relationship between the Russian and U.S. space agencies is "normal" when it comes to their partnership on the space station, despite the situation in Ukraine.

"I think people lose track of the fact that we have occupied the International Space Station now for 13 consecutive years uninterrupted, and that has been through multiple international crises," Bolden said during a news conference on March 4. "I don't think it's an insignificant fact that we're starting to see a number of people with the idea that the International Space Station be nominated for the Nobel Peace Prize. It's not trivial. It has continued to exist and continued to function with people from a variety of cultures and beliefs."

Last month, Bolden also said that without U.S. participation, the space station couldn't continue functioning as it does now. When asked what would happen if Roscosmos refused to send astronauts to the space station, Bolden explained that Russia could not operate the station without NASA.

"Because we provide navigation, communications, power … I hate to deal in conjecture," Bolden said before members of Congress during a hearing on March 27. "The partners would probably have to shut the space station down. If you're thinking that the Russians will continue to operate the International Space Station, it can't be done."

At the moment, the space station plays host to NASA astronauts Rick Mastracchio and Steve Swanson and Japanese astronaut Koichi Wakata. Cosmonauts Alexander Skvortsov, Oleg Artemyev and Mikhail Tyurin round out the outpost's Expedition 39 crew.

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This story was originally written for SPACE.com and has been republished with permission here. Copyright 2014 SPACE.com, a TechMediaNetwork company.