Russia has recently sought to overwhelm Ukraine's air defences with major attacks that include increasing numbers of decoy drones.

Facing a numerically superior foe, Ukraine is under pressure to replenish its ranks on the battlefield where, after three years of war, recruitment is already a challenge.

In symbolic rulings, Moscow was again blamed for the downing of Flight MH17 in 2014 and for an array of war-related human rights violations, including the transfer of Ukrainian children to Russia.

Europe's top human rights court ruled that Russia was responsible for widespread violations of international law in Ukraine, including the downing of Malaysia Airlines Flight 17 in 2014, marking the first time an international court has held Moscow accountable for human rights abuses related to the conflict there.

The European Court of Human Rights delivered two of four rulings against Russia in an international inquiry brought by Ukraine and the Netherlands.