KIEV, Jan. 16 - Outgoing U.S. Vice President Joe Biden on Monday urged the international community to stand against what he called Russian aggression and urged the incoming administration of President-elect Donald Trump to be a strong supporter of Ukraine, RFE/RL reported.

Biden’s visit to Kiev, his sixth during President Barack Obama's eight years in office and fifth since Moscow-friendly President Viktor Yanukovych fled in the face of the Euromaidan protests in February 2014 and a pro-Western government came to power, came four days before Trump's January 20 inauguration.

Speaking alongside Ukrainian President Petro Poroshenko, whom he described as his "good friend," Biden said U.S. sanctions imposed on Russia for its seizure of the Crimean Peninsula and its involvement in a war between government forces and pro-Moscow separatists in eastern Ukraine must remain in place until Moscow fully implements its commitments under a 2015 peace deal known as the Minsk accords.

Biden said he knows it is hard to find faith in the Minsk process when Russia refuses to hold up its end of the deal, in his words, but he emphasized that it is "Ukraine’s best hope to move forward as a united country."

The outgoing U.S. vice president urged Ukraine to keep demonstrating its commitment to the rule of law and fighting corruption. He said Ukrainians must insist on transparency and "investigate and prosecute government officials who siphon off funds for their own enrichment."

Russia, Biden said, has used corruption as a "tool of coercion" to keep Ukraine within its sphere of influence. Fighting corruption is not just a matter of good governance, it is essential for self-preservation and security, he said.

Poroshenko expressed gratitude to Biden for his unwavering support for Ukraine and invited him back to Kiev as a private citizen.

He also thanked the United States for Obama's January 13 decision extending sanctions against Russia over its seizure of Crimea and aggression in eastern Ukraine for a year, through March 2018 -- a move that means Trump will have to cancel them rather than just letting them expire in a few weeks if he wants to abandon them, as he has indicated he might.

Ukrainian officials have expressed concern that U.S. support could wane following the inauguration of Trump, who has spoken admiringly of Russian President Vladimir Putin and expressed a desire to improve ties with Moscow.

In an interview with The Times of London and the German magazine Bild published on January 16, Trump suggested he may offer to roll back sanctions against Russia in return for a deal with Moscow to reduce nuclear arms.

After reading his statement, Biden was asked by a reporter if he had received any assurances that the Trump administration would place a similar priority on Ukraine.

"Hope springs eternal," he replied before flashing a thumbs up, turning, and walking away. (rfe/ez)