"Putin got a 50-day pass to kill as many people as he can and do whatever he wants in Ukraine," Hope for Ukraine CEO told Newsweek.

Russia's Defence Ministry said on Saturday its forces had captured two more villages in eastern Ukraine, including one in Dnipropetrovsk region where Moscow says its troops have begun to make advances.

Russia and Ukraine have traded aerial attacks overnight, resulting in two deaths in each country, with many wounded on both sides.

Ukrainian drones hit Russia's Sochi resort while Russian forces bombarded Odessa's residential areas and historic Pryvoz market, hours after ceasefire talks collapsed.

Ukraine and Russia attacked targets on each other's territory on Thursday after brief direct talks between the two sides failed to make any progress on steps to end nearly three-and-a-half years of war.

Russia and Ukraine traded aerial attacks overnight, resulting in two deaths in each country, according to officials.

Fox News senior strategic analyst Gen. Jack Keane explains why Russia seems to have no interest in a ceasefire with Ukraine on 'Fox & Friends.'

Negotiators for the warring sides in Istanbul appeared to make little progress on ceasefire terms or a possible summit between their presidents – with their meeting ending after less than an hour.

The warring sides remain far apart after the third round of U.S.-brokered peace negotiations on Wednesday. But there was progress on humanitarian issues.

Peace talks and a settlement in Ukraine have never been on the real agenda of the West, Russian foreign ministry spokeswoman Maria Zakharova said on Saturday, in her first comments on negotiations since Russian and Ukrainian officials held talks on Wednesday.