KYIV: After nearly ten months of fighting in Ukraine, Moscow said no "Christmas ceasefire" was in the cards, rejecting Kyiv's call to begin withdrawing troops by Christmas as a step toward ending Europe's most significant conflict since World War Two.

Russia and Ukraine are currently not in talks to end the fighting, which is raging in the east and south with little progress on either side.

On Wednesday, the first major drone attack on Ukraine's capital in weeks returned violence to Kyiv. Two administrative buildings were hit, but air defences largely repulsed the attack. According to Ukrainian President Volodymyr Zelenskiy, 13 drones were shot down.

Residents in one Kyiv district said they heard the loud whirring engine of an Iranian Shahed drone followed by a powerful explosion at a building next to their homes.

Since Russia invaded its neighbour on Feb. 24, saying it needed to protect Russian speakers from Ukrainian far-right nationalists, tens of thousands of people have been killed, millions have been displaced, and cities have been reduced to rubble. Kiev and its allies refer to it as an unprovoked war of choice.

"There is no calm on the front line," Zelenskiy said in a regular evening video address, describing Russia's artillery destruction of towns in the east, "so that only bare ruins and craters" remain.

This week, Zelenskiy proposed that Russia begin withdrawing by Christmas as a step toward ending the conflict, but Moscow rejected the proposal, claiming that Ukraine must accept the loss of territory to Russia before any progress can be made.

"Given what we're seeing in the air and on the ground in Ukraine, it's difficult to conclude that this war will be over by the end of the year," White House national security spokesman John Kirby said in response to a question about prospects for a negotiated settlement.

More than 70 countries have pledged billions of euros ($1.1 billion) to help maintain Ukraine's water, food, energy, health and transport in face of Russian attacks. Russia has fired barrages of missiles on energy infrastructure since October, disrupting power supplies and leaving Ukrainians without heating.

The decision on whether or not to provide the system could come as soon as Thursday, officials say. Russia says such systems would be legitimate targets for attack in the post-Soviet republic.

Despite the lack of peace talks, hundreds of detainees have been freed in swaps in recent weeks. The latest exchange of dozens of detainees included a U.S. citizen, Kyiv and Washington said on Wednesday. Suedi Murekezi was reportedly "helping our people" before ending up in Russian custody.

"We certainly welcome that news," Kirby told reporters, but declined to identify the freed American due to privacy concerns.

On Wednesday, the head of the International Committee of the Red Cross said that in the Ukraine-Russia conflict, an all-for-all prisoner-of-war swap was an option. The International Committee of the Red Cross emphasized that it was up to the two countries to reach an agreement on the issue.

ICRC President Mirjana Spoljaric said a major swap could build confidence and that such exchanges had in the past constituted "the first step to a broader agreement"

Neither the Red Cross nor the two sides have provided precise numbers for each country's war detainees, but thousands of such prisoners are believed to exist.

According to media, Ukraine has pushed for more captives to be returned as part of talks with Russian representatives seeking the reopening of an ammonia gas pipeline through Ukraine. The pipeline is widely regarded as critical to lowering global fertilizer prices made from natural gas.