U.S. President Barack Obama spoke with Ukrainian President Viktor Yanukovych during a nuclear security summit in Seoul. Obama, the White House said in a readout of the conversation, expressed appreciation for Kiev's decision to completely remove highly enriched uranium from the country.
"The president underscored the importance of demonstrating the vitality of Ukrainian democracy by ensuring free, fair, and transparent parliamentary elections in October," the statement added. "The president also raised U.S. concerns about selective prosecutions of the political opposition."
Ukrainian lawmakers last week said they determined that former Prime Minister Yulia Tymoshenko likely committed treason in a 2009 gas deal with Russia. Tymoshenko is serving a seven-year prison sentence following a conviction on charges she abused her authority in the gas deal.
Tymoshenko denies any wrongdoing and her supporters say the charges are politically motivated. She helped lead the country's Orange Revolution in 2004 but lost an election to Yanukovych in 2010.