U.S. Vice President Joe Biden (left) shakes hands with Ukrainian and U.S. officials upon his arrival at Boryspil International airport outside Kyiv, Ukraine, April 21, 2014.
Pro-Russian separatists have detained a Ukrainian journalist, Irma Krat, accusing her of "war crimes" during the "Euromaidan" protests that toppled the Moscow-backed president, Slovyansk, Ukraine, April 21, 2014.
An agreement reached last week to avert wider conflict in Ukraine was faltering as the new week began, with pro-Moscow separatist gunmen showing no sign of surrendering government buildings they had seized. Here masked pro-Russian men walk past a barricade outside a regional government building in Donetsk, Ukraine, April 21, 2014.
A masked pro-Russia insurgent guards an entrance to the Ukrainian regional office of the Security Service. A Russian national flag is in the background, Luhansk, April 21, 2014.