The US claimed on Friday that Russia had supplied tanks and other heavy weapons to separatists in eastern Ukraine and warned of further “costs” to Russia if more weapons crossed the border . More On this story The state department said that in recent days three T-64 tanks, several rocket launchers and a number of other military vehicles had crossed the Russian border into eastern Ukraine . The statement was the most detailed in a series of accusations the US and other countries have made about Russian military assistance to armed groups in Ukraine and could be used as the basis to impose further sanctions on Moscow. “This is unacceptable,” said Marie Harf, spokeswoman for the US state department. “A failure by Russia to de-escalate the situation will lead to additional costs.” The US comments support an almost identical accusation made on Thursday by […]