"As soon as there is God's will, the weather and a decision by commanders, we will do it," Oleksii Reznikov said on Friday.

The Ukrainian minister said Western tanks and weapons would act as an "iron fist" in Ukraine's bid to take back its occupied territory.

His comments come as 19 people were killed in a round of Russian airstrikes - the first large-scale group of strikes in nearly two months.

Officials said 17 people were killed in the central Ukrainian city of Uman from a round of Russian missile and drone strikes.

A further two people were killed in Dnipro, a city in the southern central area, along the banks of the Dnipro River.

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The capital Kyiv was also rocked by explosions in the early hours, as were the central cities of Kremenchuk and Poltava, and Mykolaiv in the south.

Two people were wounded in the town of Ukrainka - just south of Kyiv - officials said.

In Uman, firefighters battled a raging blaze at a residential apartment building that had been struck on an upper floor by a Russian missile.

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Officials said at least 15 people were killed there, including three children - two 10-year-olds and a toddler - while a further nine people were taken to hospital.

One resident, Serhii Lubivskyi, 58, was in the block of flats when the missile struck.

"My neighbours are gone, no one is left... only the kitchens were left standing," he said.

"My flat is on the seventh floor... we felt the impact, we heard the explosion."

Another resident, Olga, said: "At first the windows were blown out, then came the explosion. Everything flew out."

Moscow has frequently launched long-range missile attacks during the 14-month war, often indiscriminately hitting civilian areas.

However, the Kremlin has denied its military aims at civilian targets.

The Russian defence ministry said the long-range cruise missiles launched overnight were aimed at places where Ukrainian military reserve units were staying before their deployment to the battlefield.

It comes as Ukraine prepares to launch its much-talked-about counteroffensive to reclaim territory taken by Russia.

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The offensive will involve tanks and weapons from Western powers, including the US, the UK and Germany.

Britain has given Challenger 2 tanks, the US has sent Abrams, while German Leopard 2 tanks have also been handed over to Kyiv for use in the offensive.

Russia, meanwhile, has been fortifying its occupied territory for months in anticipation of Kyiv's planned assault - which is widely expected once warmer weather returns.

Ukraine and its Western military backers hope a push by thousands of Ukrainian troops trained at Western bases will shift the dynamics of the war - which has mostly seen Russia on the offensive throughout winter.