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.

I STANBUL—President Trump’s ultimatum for Russian President Vladimir Putin is showing no signs of bringing Russia and Ukraine any closer to peace. The third round of direct talks between Ukrainian and Russian officials, held Wednesday in Istanbul, yielded few results. The two sides met for less than an hour.

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.