Iran conflict could open opportunities for Russia to possibly become a power broker to help end the confrontation.

It is designed to make the West think a Kremlin victory is inevitable.

Ukraine's president said that troops maintained their defensive lines along more than 1,000 kilometers of the front.

Russian forces have advanced into Dnipropetrovsk and Sumy regions, in fresh bid for Ukrainian land beyond what Moscow's already annexed.

Ukrainian officials say three people were killed and 13 were wounded when Russia attacked the country with waves of drones and missiles.

Serbia’s Russia-friendly leader made a surprise visit to Ukraine on Wednesday for a summit on strengthening European support for Kyiv's fight against Russian aggression, but he refused to sign a joint declaration calling for tougher sanctions against Moscow.

"Even if you're on the ground, it's very difficult for you to count casualties," said Marina Miron, a postdoctoral researcher at King's College London.

Russian President Vladimir Putin told his US counterpart Donald Trump Saturday that Moscow was ready to hold a fresh round of peace talks with Kyiv after June 22, once the warring sides complete exchanging prisoners and soldiers' bodies.