A top U.S. diplomat has slammed Moscow for allegedly failing to implement the commitments it made in last week's agreement in Geneva to de-escalate the conflict in Ukraine.
Speaking to journalists in Brussels on April 23, U.S. Ambassador to the Organization for Security and Cooperation in Europe (OSCE) Daniel Baer said "Russia must be constructively engaged" in the implementation of the Geneva agreement.
"So far we have not seen that," Baer said.
Baer added that implementing the agreement -- which includes disarming illegal armed formations -- should take only "days, not weeks."
Baer urged Moscow to cooperate with the OSCE monitoring mission overseeing the agreement, including calling for Russia to send a senior diplomat to help the OSCE persuade pro-Russia militant formations in eastern Ukraine to leave occupied public buildings.
Earlier in the day, Russian Foreign Minister Sergei Lavrov warned that Russia will retaliate if Russian interests in Ukraine are "attacked."
He also asserted that Moscow believes the United States is "running the show" in Ukraine.
A pro-Russian leader in Ukraine's rebel-held eastern town of Slovyansk has accused an American journalist being held by the separatists of being a spy.
Vyacheslav Ponomaryov, the self-declared "people's mayor" of Slovyansk, on April 23 confirmed that Simon Ostrovsky was being held by pro-Russian militants.
Ponomaryov said Ostrovsky holds dual U.S.-Israeli citizenship and "according to our information, is an informer for the Right Sector," a Ukrainian ultra-nationalist group.
In Washington, U.S. State Department spokeswoman Jen Psaki expressed concern about "the kidnapping of a U.S. citizen journalist" in Slovyansk. She called for Russia to use its influence to ensure that all "hostages, including journalists" being held in eastern Ukraine are released.
with additional reporting by Reuters