US Vice President Joe Biden has discussed Greece's economic future and the situation in Ukraine with Greek Prime Minister Antonis Samaras. The White House says Biden spoke to Samaras by phone on Thursday. Biden thanked the Greek leader for his country's role in NATO. The White House says they discussed upcoming elections in Ukraine and agreed it's important to stand up to Russian aggression. Biden praised Greece's efforts to reform its economy as the country struggles to pull itself out of a major debt crisis. He told Samaras the U.S. will support Greece's return to prosperity. The White House says the leaders also discussed trade, plus peace talks in ethnically split Cyprus.