Obama imposes new Ukraine sanctions

The Treasury Department announced sanctions against six "Crimean separatists," as well as a Crimean gas company, Friday in the latest move to punish Russia for annexing Crimea.

Individuals who've been sanctioned include the head of the security service in Crimea and officials in the Crimea Electoral Commission, which oversaw the March referendum where the region voted to join Russia. Separatist leaders sanctioned were: Pyotr Zima, Aleksei Chaliy, Rustam Temirgaliev, Yuriy Zherebtsov, Mikhail Malyshev, and Valery Medvedev.

Also on the list is Sergey Tsekov, who was vice speaker of Ukraine's parliament and "was responsible for facilitating the unauthorized referendum that paved the way for Russia’s illegal annexation of Crimea, " according to the Treasury Department.

The U.S. says the sanctioned company, Chernomorneftegaz, was a subsidiary of a Ukrainian state-owned gas company that was seized by the Crimean parliament in March. 

This is the third round of sanctions the United States has announced, as tension with Russia continue. Secretary of State John KerryJohn KerryFormer Obama officials say Netanyahu turned down secret peace deal: AP How dealmaker Trump can resolve the Israeli-Palestinian conflict John Kerry to teach at Yale on global issues MORE raised the prospect of more damaging sanctions on sectors of the Russian economy such as banking or energy this week. 

Russia has amassed troops on the Ukrainian border, raising fears it could move into eastern Ukraine.