Russia and Ukraine completed the exchange of 1000 prisoners each on Sunday, the Russian Defence Ministry and Ukrainian President Volodymyr Zelenskiy said, in the largest such swap since the war began three years ago.

The three-day exchange started on Friday and involved mostly prisoners of war, along with 120 civilians, each. On Sunday, both sides swapped 303 prisoners.

"Today, warriors of our Armed Forces, the National Guard, the State Border Guard Service, and the State Special Transport Service are returning home," Zelenskiy wrote on the Telegram app.

The exchange was the only concrete step towards peace to emerge from the first direct talks between the warring sides in more than three years on May 16, when they failed to agree a ceasefire.

Ukraine, the United States and other Western countries have called for a 30-day halt to fighting without preconditions to allow for peace talks.

Hundreds of thousands of soldiers on both sides are believed to have been wounded or killed in Europe's deadliest conflict since World War Two, although neither side publishes accurate casualty figures.

Tens of thousands of Ukrainian civilians have also died as Russian forces have besieged and bombarded Ukrainian cities.

On Friday, Russian Foreign Minister Sergei Lavrov said that once the exchange was completed, Moscow would be ready to present Ukraine with a draft proposal for a long-term peace agreement.

Russian forces launched a barrage of 367 drones and missiles at Ukrainian cities overnight, including at the capital Kyiv, in the largest aerial attack of the war so far, killing at least 12 people and injuring dozens more, officials said.

Russia's Defence Ministry reported that its air defense units had intercepted or destroyed 95 Ukrainian drones over a four-hour period. The Mayor of Moscow, Sergei Sobyanin, said 12 Ukrainian drones had been intercepted on their way to the capital.