The changes also raised concerns in the European Union, a key ally to Ukraine since the Russian invasion in February 2022 that has said reforms are essential for closer European integration.

Zelensky had promised on Wednesday he would propose a new bill on anti-graft agencies to parliament, a move the EU welcomed.

"I have just approved the text of a draft law that guarantees real strengthening of the rule of law in Ukraine, independence of anti-corruption bodies and reliable protection of the rule of law from any Russian influence or interference," Zelensky wrote on social media.

He said the new bill would be submitted to parliament on Thursday.

"It is important that we respect the position of all Ukrainians and are grateful to everyone who stands with Ukraine," he added.

Thousands took to the streets across Ukraine this week to protest against changes that would remove the independence of key anti-graft agencies;

They were the country's first large-scale demonstrations since the war started more than three years ago.

That law -- swiftly approved by the parliament and signed by Zelensky on the same day -- places the National Anti-Corruption Bureau of Ukraine (NABU) and Specialised Anti-Corruption Prosecutor's Office (SAPO) under the direct authority of the prosecutor general, who is appointed by the president.