KYIV — One of Ukrainian President Volodymyr Zelensky's key aides has resigned ahead of an expected government reshuffle.

Kyrylo Tymoshenko was the president's deputy head of office and thanked Zelensky for "the opportunity to do good deeds every day and every minute".

He had been implicated in scandals linked to his use of expensive cars - though he denies wrongdoing.

Zelensky has signaled that other top officials will also leave his government in the coming days.

The Ukrainian leader has said he is carrying out a series of personnel changes in government, regional authorities and the security services.

Local media reported that the departure Tymoshenko - who oversaw regional policy and earlier worked on Zelensky's election campaign - may be part of the president's shake-up.

But the restructure comes amid a clampdown on corruption in Ukraine, one of the EU's key demands if the country is to advance its application to join the bloc. Authorities have banned all state officials from leaving Ukraine, unless on authorized business trips.

On Monday, Ukraine's deputy infrastructure minister Vasyl Lozinskyi was fired and detained by police after being accused of accepting a bribe worth $400,000 (£320,000). He has denied the charges.

Ukraine has a history of corruption and in 2021 Transparency International has ranked the country at 122 out of 180 countries in its ranking of corrupt states.

In an address on Sunday, Zelensky promised there would be "no return to what used to be in the past, to the way various people close to state institutions" used to live.

And David Arakhamia, the head of Zelensky's Servant of the People party, has pledged that corrupt officials could face jail time.

"Officials at all levels have been constantly warned through official and unofficial channels: focus on the war, help the victims, reduce bureaucracy and stop doing dubious business. Many of them have actually listened, but some, unfortunately, did not," he said in a Telegram statement.

"If it doesn't work in a civilized way, it will be done according to the laws of wartime. This applies both to recent purchases of generators and to fresh scandals in the ministry of defense."

Defense Minister Oleksii Reznikov has also come under fire recently, following media reports suggesting his ministry signed a contract to procure food for the military at inflated prices. Reznikov said those prices were a "technical mistake".

A report by Ukrainian newspaper Ukrainska Pravda suggests the heads of four regional administrations - Sumy, Dnipro, Zaporizhzhia and Kherson - may be the next to go after Tymoshenko, due to their links to the resigned presidential aide. — BBC