UN Secretary-General Ban Ki-moon has voiced his alarm over the escalating Ukraine crisis in a phone call with Russian President Vladimir Putin.
"The Secretary-General ... underlined that any deepening of the crisis would be profoundly detrimental for all concerned; hence the need for everyone to work to de-escalate the situation," a statement from Ban's office read.
Tensions remain high in eastern Ukraine after at least three died in a day of shooting during what was supposed to be an Easter truce.
In an exclusive interview with NBC News, the Ukrainian Prime Minister warns of the dangers of unchecked Russian expansion and aggression.
Russia, the US and the EU say that all sides have agreed to steps to "de-escalate" the crisis in Ukraine at talks in Geneva.