Russia casts doubt on US' future with the ISS over Ukraine sanctions

The head of Russia’s space program says Moscow will reject the United States’ request to use the International Space Station beyond 2020 – the latest twist in a standoff between the two countries over the ongoing crisis in Ukraine.

Deputy Prime Minister Dmitry Rogozin, who leads Russia’s defense industry, made the announcement Tuesday. He also said Russia will block Washington from using Russian-made rocket engines to launch military satellites, according to Reuters.

The moves come after the U.S. slapped sanctions on Russian President Vladimir Putin’s allies -- who include Rogozin -- for Russia's intervention in Ukraine. The U.S. also denied export licenses for high-tech items that could aid Russia’s military.

"These sanctions are out of place and inappropriate," Rogozin said at a news conference Tuesday. "We have enough of our own problems."

Russia supplies NK-33 and RD-180 rocket engines to the U.S.

"We are ready to deliver these engines but on one condition -- that they will not be used to launch military satellites," Rogozin said.

A Kremlin-controlled firm that Rogozin oversees produces and supplies the RD-180 engine to American defense contractors.

The United Launch Alliance (ULA), a joint venture of Boeing and Lockheed-Martin which sub-contracts with the Kremlin-controlled firm for the engines, said Tuesday that it is “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,” Jessica Rye, a spokesperson for the ULA, told Fox News in a statement.

After the sanctions were announced, Rogozin took to Twitter last month and said Russia would retaliate against the U.S.

"I propose that the United States delivers its astronauts to the ISS with the help of a trampoline," he added.

The U.S. wants to keep the ISS in use until at least 2024, according to Reuters. But as of now, Russian Soyuz spacecraft are the only way American astronauts can get to the ISS. NASA is working to restore U.S. transport to the station by 2017.

Rogozin said Russia is planning changes to its space industry after 2020 and plans to divert money and resources to "a project with more prospects".

He also suggested that Russia could use the station without cooperation from the U.S.

"The Russian segment can exist independently from the American one,” Rogozin said. “The U.S. one cannot."

Click for more from Reuters.

Fox News' James Rosen contributed to this report.