A Ukrainian military convoy stops on the road between the towns of Debaltseve and Artemivsk, Ukraine, on Saturday, hours before a cease-fire agreement is set to go into effect. Petr David Josek/AP hide caption

itoggle caption Petr David Josek/AP

Ukrainian President Petro Poroshenko, left, German Chancellor Angela Merkel and U.S. Vice President Joe Biden, background right, arrive for a meeting in Munich, Germany on Saturday. Matthias Schrader/AP hide caption

itoggle caption Matthias Schrader/AP

Ukraine's president Petro Poroshenko speaks at a meeting of the National Security and Defense Council (NSDC) of Ukraine on Sunday. Mykola Lazarenko/ITAR-TASS/Landov hide caption

itoggle caption Mykola Lazarenko/ITAR-TASS/Landov

Igor Girkin, a Russian citizen who headed the pro-Russian rebels in eastern Ukraine last year, walks with his bodyguards in the eastern Ukrainian city of Donetsk in July. Alexander Khudoteply/AFP/Getty Images hide caption

itoggle caption Alexander Khudoteply/AFP/Getty Images

Russian President Vladimir Putin speaks in front of the map of the Russian Federation, with Crimea on the left of the map, during his annual news conference in Moscow, Russia, on Thursday. The Kremlin has responded angrily to the latest round of U.S.-EU sanctions over the annexation of Crimea. Alexei Druzhinin/AP hide caption

itoggle caption Alexei Druzhinin/AP

A pro-Russian rebel fighter guards an area of the Malaysia Airlines Flight 17 crash site in the village of Hrabove, Donetsk region, eastern Ukraine, earlier this week. Investigators erect a "no trespassing" sign in the background. Mstyslav Chernov/AP hide caption

itoggle caption Mstyslav Chernov/AP

Russian President Vladimir Putin looks to his side during the family photo session of the G-20 summit in Brisbane, Australia, on Saturday. Putin was sternly criticized by Western leaders over Moscow's involvement in eastern Ukraine. Rob Griffith/AP hide caption

itoggle caption Rob Griffith/AP

A pro-Russian separatist casts a ballot during the self-proclaimed Donetsk People's Republic leadership and local parliamentary elections at a polling station in the southern coastal town of Novoazovsk on Sunday. Maxim Zmeyev/Reuters/Landov hide caption

itoggle caption Maxim Zmeyev/Reuters/Landov

Ukrainian lawmakers applaud a televised address by the President of the European Parliament Martin Schulz (on screen) in the Ukrainian parliament on Tuesday in Kiev. The parliament voted to strengthen trade ties with the EU, but not until 2016. Sergey Dolzhenko/EPA/Landov hide caption

itoggle caption Sergey Dolzhenko/EPA/Landov