U.S. Secretary of State John Kerry has called Russian Foreign Minister Sergei Lavrov to express “grave concern” about the sharp increase in separatist attacks in eastern Ukraine, the State Department said.
According to a State Department spokesman, Kerry also urged for an immediate cease-fire to take place.
Ukraine said two soldiers had been killed in the heaviest clashes with pro-Russian separatists in eastern Ukraine since a fragile cease-fire was negotiated in Minsk in February.
Kerry also expressed concern about the visit by Iranian elite Quds force leader Qasem Soleimani to Moscow in late July.
The spokesman said the visit would be discussed with Russia at an upcoming New York meeting on violent extremism.
Soleimani is one of several Iranian officials targeted by a 2007 UN travel ban because of their alleged links to Iran's nuclear or ballistic-missile programs.