Washington: US Secretary of State John Kerry told his Russian counterpart Sergei Lavrov of his "concern" Friday over the escalation of violence in eastern Ukraine and urged Moscow and pro-Russian separatists to respect a faltering ceasefire.
Kerry telephoned the Russian foreign minister and they had a 10-minute conversation, State Department spokeswoman Jen Psaki said, as Ukrainian forces clashed with pro-Russian insurgents over control of a strategic airport in the east of Ukraine.
"He called to express his concern about intensifying violence in eastern Ukraine," Psaki said.
"He also underscored that Russia and the separatists they back must immediately implement their obligations under the September 5 ceasefire agreement and September 19 implementing agreement they signed in Minsk, including a secure Russian-Ukrainian border."
The two sides in the conflict are four weeks into their shaky truce, but there have been many violations, including the latest battle for the flashpoint transport hub north of Donetsk.
The five-month-old conflict has killed more than 3,200 people and despite repeated violations of the truce, Western leaders still view it as the only viable option for ending Europe`s worst crisis in decades.
Psaki said that more than 200 people, "many of them innocent men, women and children," had died since September 5, including a Swiss aid worker.
"Innocent people continued to suffer and die," said Psaki.
"Russia must use its influence with the separatists to end these attacks immediately and stop the flow of weapons, equipment and militants into Ukraine," she added.
"Russia must also withdraw all of its military forces and equipment including the Russian fighters it is supporting from inside Ukraine."
Moscow has consistently denied backing the rebels.