NASA is halting most communication with the Russian government except for the International Space Station, citing Russia’s violations of Ukraine’s sovereignty, according to a internal memo from the U.S. space agency.

The suspension includes NASA visits to Russia and visits by Russian officials to NASA facilities, as well as meetings, teleconferences and email exchanges, the memo says.

NASA confirmed the suspension in an online statement: “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.”

NASA also stated it is “laser focused on a plan to return human spaceflight launches to American soil, and end our reliance on Russia to get into space.”

The agency said it had plans for human spaceflight next year from the United States, but with reduced funding levels approved by Congress, the launch will now be in 2017, according to the statement.

Currently, two American astronauts are on the ISS.

Follow @JolieLeeDC on Twitter.