Both leaders voiced their strong -- and opposing -- viewpoints regarding the cause of the crisis.
Merkel laid blame on Russia, expressing her "great concern over the tense situation in eastern Ukraine and said she expects that the Russian government must avow itself to the Geneva agreement and that it collaborates with the implementation," said spokesman Steffan Seibert.
She called on Putin to implement the Geneva accord reached a week earlier in which Ukraine and Russia agreed that all illegal military entities be disbanded, all occupants of seized buildings disarmed and evacuated, and all protesters granted amnesty.
Putin blamed Ukrainian officials for contributing to the unrest in eastern Ukraine by their "unwillingness to implement the Geneva agreements" and "condemned the Kiev authorities' attempts to use armed forces against civilians in Ukraine's southeast regions."
After the four party talks concluded with the signing of the Geneva agreement on April 17, U.S. Secretary of State John Kerry warned Russia not to renege on its commitment to de-escalate the crisis in Ukraine.
"I made clear to Foreign Minister Lavrov today that if we’re not able to see progress on the immediate efforts to be able to implement the principles of this agreement this weekend, then we will have no choice but to impose further costs on Russia."
Since the agreement was reached, pro-Russian militants have detained journalists, reportedly abducted OSCE military monitors, Russia continues to amass troops near the border of Ukraine, and the Russian defense ministry ordered military drills along the border as a response to Ukraine's anti-terror operations.