Spokesperson for the U.S. Department of State Heather Nauert said this at the press briefing in Washington on Thursday, an Ukrinform correspondent reports.
"The last 24 hours were considered the deadliest one-day period in 2017. In this time period, eight Ukrainian soldiers have now been killed, including five deaths in an attack which appears to have been initiated by Russian-led forces," the spokesperson said.
Nauert called on Russia and "the forces that it arms, trains, and leads in the east to immediately observe the ceasefire."
To this end, the spokesperson for the U.S. Department of State stressed, "those forces must withdraw all heavy weapons, disengage from the line of contact, and allow full, safe, and unfettered access to the OSCE monitors to the international border."