Russia has threatened to cut off a supply of rocket engines that are crucial to the U.S. space program in retaliation for surprise sanctions over the Skripal poisoning. The U.S. announced Wednesday it would impose new sanctions after Washington determined Moscow had used a nerve agent against Russian former spy Sergei Skripal and his daughter, Yulia. Dawn Sturgess, a mother of three, died after coming across remnants of the poison, which also affected her boyfriend, Charlie Rowley. Russia continues to deny any involvement in the attempted murders using a Soviet-era nerve agent known as Novichok. “On August 8, 2018 our Deputy Chief of Mission was informed in the State Department of new ‘draconian’ sanctions against Russia for far-fetched accusations of using the ‘Novichok’ nerve agent against a U.K. citizen,” the embassy said in a statement. “We grew accustomed to not hearing any facts or evidence.” The value of the Russian ruble slid by more than 1 percent against the dollar Thursday, a day after falling toward its lowest level in nearly two years. The Russian embassy said it continued to advocate for a transparent investigation into the poisoning.