President Zelensky has called Ukraine’s air defence supplies “insufficient”, having revealed several systems were “without missiles” until Friday morning.

“I can say this openly because today I have those missiles,” the president said, adding that the country had received a “substantial package” earlier in the day.

His comments follow days of intense Russian bombardment of Ukraine’s energy infrastructure, which has left thousands of people without heating and electricity during a bitterly cold winter.

Schools in Kyiv will shut until February, the capital’s mayor announced later in the day, as the city continues to face severe energy shortages amid temperatures which have dropped as low as -19C.

Zelensky called on Ukraine’s allies to provide “rapid deliveries” of available missiles, and said shipments did not mean “that winter will end for us tomorrow”.

“And it doesn’t mean that tomorrow the enemy will stop bombing us,” he wrote on social media.

Ukraine relies on its Western partners for several vital air defence systems, which Zelensky said required a “constant supplies of missiles”.

“Securing these packages takes enormous effort, blood, and human lives.”

He criticised countries that “stockpiled” such ammunition: “If we are at war, we really need it. And in some countries, there is no war.”

On Friday evening, he said Ukraine had “intelligence information” that Russia was preparing for large-scale strikes.

“Supplies are insufficient,” he wrote on Telegram. “We are trying to speed things up, and it is important that our partners hear us.

Earlier this week, Kyiv declared a state of emergency in its energy sector and appointed former prime minister Denys Shmyhal as energy minister to tackle the situation.

Ukrainian officials also accused Moscow of deliberately exploiting an extraordinarily cold winter.

Shmyhal told Ukraine’s parliament on Friday that Moscow was “betting it can break us through energy terror”, and ordered state companies to increase their energy imports.

Thousands of energy workers are racing to restore power across the country through repairing plants and substations bombarded by Russian strikes.

Kyiv’s Mayor Vitali Klitschko said most of the capital had been left without heating and a “huge shortage of electricity” for the first time in the war.

He told Reuters news agency that electricity levels had dropped to less than half of what was needed.

Curfews in the city, introduced after Russia launched its full-scale invasion of Ukraine in February 2022, have been eased to allow residents to access emergency hubs providing heating and electricity.

Klitschko had suggested earlier this week that residents should leave Kyiv if possible, to help ease pressure on critical resources.

Also on Friday, Zelensky said Ukrainian negotiators were on their way to the US for further talks on a potential ceasefire.

He said he hoped proposals would be signed with the US during next week’s World Economic Forum meeting in Davos, Switzerland “if everything is finalised and if there is agreement from the American side”.

Meanwhile, Russian strikes continued into Friday, including in the central Ukrainian city of Nikopol, where officials said two people had been killed.