At least six Ukrainian officials, including members of the cabinet, have stepped down from their positions ahead of an anticipated major government reshuffle.

The resignations leave some of the government's top jobs vacant, including the strategic industries minister in charge of weapons production.

The changes come as the parliamentary leader of the ruling Servant of the People party said half of the cabinet would be changed in a major government reshuffle this week.

The switch-up comes as Ukraine continues to deal with the daily Russian bombardment of its cities, and is struggling to hold back Moscow's gains in the east while also ploughing resources into its incursion in Russia's Kursk region.

Those who handed in their resignations on Tuesday included strategic industries minister Alexander Kamyshin, justice minister Denys Maliuska, environmental protection minister Ruslan Strilets, deputy prime ministers Olha Stefanishyna and Iryna Vereshchuk, and the head of Ukraine's Sate Property Fund Vitaliy Koval.

One of the president's most senior aides, Rostyslav Shurma, was also dismissed as per a presidential decree.

Writing on Telegram, David Arakhamia, the parliamentary leader of the ruling Servant of the People party, said: "As promised, a major government reset can be expected this week. More than 50% of the Cabinet of Ministers' staff will be changed.

"Tomorrow we will have a day of dismissals, and the day after that a day of appointments," he added.

Speaking during his nightly video address, Ukrainian President Volodymyr Zelensky said state institutions "should be configured so that Ukraine achieves all the results that we need" ahead of a planned visit by him to the US next month, where he is expected to present a "victory plan" to President Joe Biden.

"For this, we must strengthen some areas of the government and changes in its make-up have been prepared. There will also be changes in the (president's) office," he said.

Opposition MP Iryna Gerashchenko criticised the government's reshuffle, stating that this is "a government without ministers. A parliament without a mono-majority. An intellectual and personnel crisis to which the authorities turn a blind eye."

She called for a unity government and the end of President Zelensky's political team's grip on power.

On the same day as the changes were announced, a Russian strike on the central city of Poltava killed 51 people and injured a further 271.

President Zelensky promised Russia would pay for the attack, and repeated calls for more air defences to be supplied from Western powers "that can protect us from Russian terror".

President Zelensky has revamped his government several times since Russia launched its full-scale invasion of Ukraine in February 2022.

In May last year, he sacked defence minister Oleksii Reznikov after a series of corruption scandals, and sacked Kyiv's top commander Valerii Zaluzhnyi earlier this year.

At least five government portfolios, including the infrastructure and agriculture portfolios, have remained vacant since ministers either stepped down or were dismissed earlier this year.

Zelensky's first presidential term was due to end in May 2024, but he remains in his position under martial law.