Ukrainian Foreign Minister Dmytro Kuleba resigned Wednesday as President Volodymyr Zelenskyy oversees a major Cabinet reshuffle in Kyiv.

More resignations and appointments were expected over the coming days after five ministers stepped down Tuesday, in what a senior presidential ally cast as the start of a government "reset" ahead of the winter.

Kuleba's resignation letter was posted on Facebook by the speaker of parliament, Ruslan Stefanchuk.

The speaker said lawmakers would shortly discuss the request. Parliament expects to vote on the resignations later Wednesday in what is usually a political formality.

Zelenskyy has said changes to the government, which come at a crucial juncture in the full-scale conflict, are necessary to strengthen it and achieve the results needed by Ukraine.

"Autumn will be extremely important for Ukraine. And our state institutions should be configured so that Ukraine achieves all the results that we need – for all of us," he said Tuesday.

Russian forces are advancing in the east of Ukraine, Ukrainian troops have made a bold incursion into Russia's Kursk region and Moscow has intensified drone and missile attacks in recent weeks.

On Tuesday, at least 41 people were killed and 180 others injured in a Russian strike on a military academy in central Ukraine's Poltava.

David Arakhamia, a senior lawmaker for Zelenskyy's party, said Tuesday there would be a "major government reset" that would see more than half of the ministers change.

'More energy'

Later Wednesday Zelensky said his government needed the reshuffle to infuse "new energy."

"We need new energy. And these steps are related to strengthening our state in various areas," he said when asked about the reshuffle and Kuleba's future.

"I am very grateful to the ministers and the entire Cabinet team who have been working for Ukraine, for the sake of Ukrainians, for four and a half years and some of them have been our ministers for five years," he added.

A source close to the presidential office told AFP that Zelenskyy and Kuleba "will discuss and decide" his future post.

Kuleba – the face of Ukrainian diplomacy during the war – is the most senior of the ministers to offer to step down.

The 43-year-old has held the post since 2020 and since Russia's 2022 attack has traveled the world to advocate for Western support for Kyiv and sanctions on Moscow.