U.S. Vice President Joe Biden has expressed U.S. concern over Ukraine's recent elections to Ukrainian President Viktor Yanukovych.
Ukraine's opposition and the West say the October 28 parliamentary poll -- won by Yanukovych's party -- was marred by irregularities.
Biden expressed Washington's interest in "enhancing its relationship" with Kyiv, according to the White House.
But Biden "voiced concerns over Ukraine's recent parliamentary elections and asked President Yanukovych to ensure the process is completed in a fair and transparent manner," according to a White House statement.
Biden also urged Ukraine to live up to its democratic commitments and end selective prosecutions.
One of Yanukovych's rival, Yulia Tymoshenko, whom he beat in 2010 presidential elections, is serving a seven-year sentence for abuse of office in a case her supporters and the West suspect was politically motivated.
Tymoshenko is now facing another trial for tax evasion and embezzlement.
Biden spoke to Yanukovych by phone to thank the Ukrainian leader for his congratulatory message following Barack Obama's reelection as U.S. president.
Based on AFP reporting