Ukrainian President Volodymyr Zelensky used his country’s Independence Day to confirm a commitment not just to peace but to “victory”.

Mr Zelensky said he was confident his country would recapture annexed Crimea and occupied areas in the east.

The streets of central Kyiv were unusually empty following days of dire warnings of ‘‘repugnant Russian provocations’’ and ‘‘brutal strikes’’.

By Wednesday night (local time) the worst atrocity of the day was committed on a train carrying civilians.

At least 22 people were killed and 50 more wounded when Russian rockets hit the train in the small town of Chaplyne, 145 kilometres west of Donetsk.

“Four passenger wagons are now on fire. As of now, at least 15 people have been killed and around 50 people have been wounded,” Mr Zelenskiy said on Thursday morning (Australian time).

“Rescuers are working but, unfortunately, the death toll could increase.”

Russia has repeatedly denied its forces are aiming at civilian targets.

In April, at least 57 people died when Russian missiles hit the train station in the town of Kramatorsk, Ukrainian official said.

Celebrating independence despite constant threat

In a recorded speech aired on the six-month anniversary of Russia’s February 24 invasion, Mr Zelensky said Ukraine no longer saw the war ending when there was peace, but when Kyiv was actually victorious.

‘‘A new nation appeared in the world on February 24 at 4 in the morning. It was not born, but reborn. A nation that did not cry, scream or take fright. One that did not flee. Did not give up. And did not forget,’’ he said.

The 44-year-old wartime leader delivered the speech in his trademark combat fatigues in front of Kyiv’s central monument to independence from the Russia-controlled Soviet Union.

‘‘What for us is the end of the war? We used to say peace. Now we say victory,’’ he said.

Mr Zelensky said he would be rewarding people such as railway personnel, emergency services workers, electricians, drivers, artists and those in the media to mark the day.

The government laid out the carcasses of burnt-out Russian tanks and armoured vehicles like war trophies in central Kyiv in a show of defiance.

Authorities urged people to take air raid warnings seriously and seek shelter when sirens sound.

‘‘We are fighting against the most terrible threat to our statehood and also at a time when we have achieved the greatest level of national unity,’’ Mr Zelensky said.

The Kyiv city administration banned large public gatherings until Thursday, fearing a crowd of celebrating residents could become a target for a Russian missile strike.

‘‘They will receive a response, a powerful response,’’ Mr Zelensky said on Tuesday.

One area of deep concern to the warring parties and other countries are the circumstances at the Russian-occupied Zaporizhzhia nuclear power plant in the southern Ukrainian city of Enerhodar.

Russia and Ukraine have repeatedly accused each other of firing at the plant.

In an indication of some progress toward the plant being inspected by an independent monitor, the UN nuclear watchdog on Tuesday said it will visit within days if talks to gain access succeed.

‘‘I’m continuing to consult very actively and intensively with all parties,’’ International Atomic Energy Agency (IAEA) chief Rafael Grossi said in a statement.

Pro-Moscow forces took over the plant soon after the invasion began but it is still operated by Ukrainian technicians.

The United Nations has called for the area to be demilitarised.

-with wires