Russia said Wednesday it was ready to send humanitarian aid to Ukraine's eastern regions, and expected a prompt response from Kiev to facilitate the deliveries.

"Russia receives insistent pleas from conflict zones in eastern Ukraine for urgent humanitarian aid," the Foreign Ministry said in a statement.

Noting the ongoing military operation in those regions had led to numerous casualties, Russia urged Ukrainian authorities to undertake all measures to provide aid delivery promptly.

The aid would consist mostly of medical products, it said, adding the delivery routes should be agreed and secured.

Since Ukraine's political crisis became acute in February, Moscow has warned of a looming humanitarian catastrophe in the country.

In March, Federal Migration Service head Konstantin Romodanovsky said Russia was concerned by symptoms of a "growing humanitarian catastrophe" in Ukraine.

During recent operations by Ukraine troops and pro-government paramilitary in the rebellious Donetsk region up to 100 people, including civilians, have been reportedly killed.