By Yeganeh Torbati
WASHINGTON (Reuters) - The United States imposed further Russia and Ukraine-related sanctions on Thursday, adding associates of a billionaire Russian gas trader, Crimean port operators and former Ukrainian officials to its list of those it is penalizing in response to Russia's actions in Ukraine.
The U.S. Treasury Department's Office of Foreign Assets Control (OFAC) imposed measures against eight entities and people it said were providing support to Gennady Timchenko, a prominent gas trader previously sanctioned.
It also targeted two entities it said were providing support to Boris Rotenberg, a Russian businessman and ally of Russian President Vladimir Putin.
The measures are meant to compel Russia to comply with peacekeeping commitments signed this year in Minsk that would end fighting in eastern Ukraine, in which pro-Russian separatists are battling Ukrainian forces.
"Today's action underscores our resolve to maintain pressure on Russia for violating international law and fueling the conflict in eastern Ukraine," Acting OFAC Director John Smith said in a statement.
The United States on Thursday also sanctioned four former Ukrainian officials and their close associates linked to former Ukrainian President Viktor Yanukovych, who fled to Russia last year after being toppled by months of street protests.
Five Crimean port operators and one ferry operator were sanctioned for operating in the Crimea region of Ukraine, which was annexed by Russia in 2014.
The United States also identified several entities it said were subsidiaries of VEB and Rosneft, the Russian state development bank and flagship oil giant, which were sanctioned last year.