Fighting has started again in eastern Ukraine between government troops and separatist rebels, Ukrainian military officials said.
Yesterday a missile killed at least 15 refugees who were trying to flee the area "burning them alive". More bodies may still be recovered.
This comes days after a convoy of aid supplies travelled to the country from Moscow but Ukraine is still to let them in over fears it could spark an invasion.
Russia's Foreign Minister Sergei Lavrov has called for "urgent measures for preventing an impending humanitarian catastrophe" in Ukraine during a telephone call with US counterpart John Kerry, his department says.
A statement from the Russian Foreign Ministry said Kerry "confirmed such work is being carried out with the Kiev authorities".
The statement follows reports that Ukrainian forces had surrounded the rebel-held city of Donetsk in the east of the country.
The Democratic presidential candidate may also have shown his cards on his choice of running mate.
The US president also shared a post on Twitter accusing Dr Anthony Fauci of misleading the public over hydroxychloroquine.
Fears over an impending second wave of coronavirus dominates Wednesday’s front pages.