Ukrainian President Volodymyr Zelensky has named spy chief Kyrylo Budanov as his new chief of staff, just over a month after his previous top aide resigned amid a corruption row.

"At this time, Ukraine needs greater focus on security issues," Zelensky said in a post on social media, publishing a photo of his meeting with Budanov in Kyiv.

Budanov, 39, has until now led the Hur military intelligence, which has claimed a number of highly-effective strikes against Russia.

Zelensky also said he intended to replace his defence minister Denys Shmyhal, appointing his current minister of digital transformation Mykhaylo Fedorov to take up the post.

Budanov's predecessor, Andriy Yermak, wielded enormous political influence throughout Russia's full-scale invasion launched in 2022. He also led Ukraine's negotiating team in crucial talks with the US aimed at ending the war.

In Friday's post on social media, Zelensky wrote: "At this time, Ukraine needs greater focus on security issues, the development of the defence and security forces of Ukraine, as well as on the diplomatic track of negotiations.

"Kyrylo has specialist experience in these areas and sufficient strength to deliver results."

The president added that he had already instructed his new office chief to update and present key documents regarding "the strategic foundations" of Ukraine's defence.

The chief of presidential staff in Ukraine is historically a very powerful position. There was a time in the 2000s when a presidential administration head in Ukraine wielded about as much power as the president himself.

Ostensibly administrative, the role traditionally offered not just close access to the head of state, but also plentiful opportunities to pull the strings of government.

For example, the chief of presidential staff could lobby for government appointments and apply pressure to business circles, often resulting in personal gain.

General Budanov's appointment suggests an intention to overhaul the role. It puts the president's office on a war footing - it will very likely be much more focused on security and the war with Russia.

Later on Friday, Zelensky announced other changes to his top team. He said Fedorov had been nominated to serve as his new defence minister because he had "decided to change the structure of the Ukrainian ministry of defence".

Federov, aged 34, is the youngest minister in the Ukrainian government. His key achievement so far is the development and implementation of Diya, a centralised digital platform for government services.

He is "deeply involved with drones", and will be tasked in particular with training more drone operators, Zelensky said in his evening address.

He added that Shmyhal remains "part of the team" and will be moved to another area of work.

Zelensky said Budanov was being replaced by 56-year-old foreign intelligence chief Oleh Ivashchenko.

Budanov's predecessor, former chief of staff Yermak, 54, stepped down on 28 November, and his departure was seen as a major blow to Zelensky.

Yermak quit shortly after his home in Kyiv was raided by the country's anti-corruption agencies.

He is not accused of any wrongdoing, and the anti-corruption bureau Nabu and specialised anti-corruption prosecutor's office Sap did not explain why they searched his property.

In the past few months investigators have linked several high-profile figures to an alleged $100m (£75m) embezzlement scandal in the energy sector.

They said they had uncovered an extensive scheme to take kickbacks and influence state-owned companies including state nuclear energy firm Enerhoatom.

The corruption scandal has rocked Ukraine, weakening Zelensky's own position and jeopardising the country's negotiating position at a delicate time.

Kyiv, backed by its European allies, is seeking to change the terms of a US-led draft peace plan originally seen as heavily slanted towards Russia.

Russian officials have seized on the scandal, talking up corruption claims.

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