Ukraine and Russia agreed to a troop exchange Sunday. Ukraine released nine Russian paratroopers in exchange for 63 Ukrainian soldiers, Reuters reported. The paratroopers reportedly got lost and entered Ukrainian territory, ITAR-Tass said. The 63 Ukrainian troops crossed into Russia as they were fleeing from combat in eastern Ukraine, the Wall Street Journal reported.

Tensions between the two countries have escalated as Ukraine and western governments accuse Russia of sending 1,000 troops into the country to support pro-Russian separatists. The assistance has led to a renewed push from the separatists, causing Ukrainian forces to lose ground and trapping hundreds of soldiers, the Journal said. Ukrainian President Petro Poroshenko and Russian President Vladimir Putin will discuss a potential cease-fire Monday in Minsk, Belarus.

"The negotiations were difficult. But commonsense prevailed and everything ended well," Maj. Gen. Alexei Ragozin said in regard to the troop exchange, ITAR-Tass reported. As part of the exchange, the surrounded Ukrainian troops were supposed to have a safe retreat but Ukraine said there were heavy casualties despite the promise, the Journal said.

Poroshenko met Saturday with the European Union officials to discuss Russian involvement. The EU is evaluating new economic sanctions against Russia based on the country's involvement in the conflict between Ukrainian forces and pro-Russian separatists, a move that has the support of the United States, Reuters reported.

"We welcome the European Council's consensus today to show strong support for Ukraine's sovereignty and territorial integrity and to prepare further sanctions for consideration in coming days," White House National Security spokeswoman Caitlin Hayden said in a statement.

Putin's comments regarding possible statehood for eastern Ukraine also drew controversy. Putin spokesperson Dmitry Peskov denied that interpretation.