Ukraine has given Moscow until Saturday to account for its military presence near the southeastern border while Russia demanded that the U.S. force Ukrainian authorities to halt a military operation in the region that has already led to the deaths of up to five rebels.
In a statement in response to remarks by the Russian Defense Minister Sergei Shoigu earlier in the day announcing exercises linked to tension in Ukraine, the Ukrainian Foreign Ministry said Russia was trying to influence Kiev's efforts to fight militants in the east.
It said that under the Vienna Document of the Organization for Security and Cooperation in Europe it was entitled to an account of the goals and other details of the exercises within 48 hours of its request — namely noon GMT on Saturday.
"Conducting Russian exercises close to the Ukrainian border cannot but raise concerns, especially after the recent declaration by the Russian Foreign Minister, containing an unambiguous hint about the possibility of Russian troops entering Ukrainian territory," the ministry said.
U.S. Defense Secretary Chuck Hagel also voiced concern at the reports of military activity along the Russian-Ukrainian border and said he was trying to arrange a call with conterpart Shoigu.
“This is dangerously destabilizing and it's very provocative. It does not de-escalate. In fact, these activities escalate. They make it more difficult to try to find a diplomatic, peaceful resolution to that issue," Hagel said.
Putting the onus on Washington to ease tensions after Ukrainian forces killed up to five pro-Moscow rebels, the Russian Foreign Ministry however said the situation "demands urgent actions to force the Kiev authorities, who are wards of the U.S., to restrain themselves and not use force".
"We are counting on the U.S. to take urgent measures in the interests of de-escalation," it said in a statement.
"Washington must force the current Ukrainian leadership to immediately stop the military operation in southeastern Ukraine and withdraw military units to their permanent bases."
"So far, nothing has been done to resolve this urgent task," it said. "We hope that Washington understands the full measure of its responsibility for what is happening."
Telephone talks planned for Wednesday and Thursday between Foreign Minister Sergei Lavrov and U.S. Secretary of State John Kerry had not taken place "for reasons that did not depend on Moscow," the Russian Foreign Ministry said.
It said that in advance of a conversation between Kerry and Lavrov scheduled for Friday, Russia "once again insistently calls on Washington to use all its influence on the interim government in Kiev" to prevent it from taking steps that could plunge Ukraine deeper into crisis.