The change also raised concerns in the European Union, a key ally to Ukraine in its war against Russia, which 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.

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

Zelensky also discussed the bill, due to be submitted to the parliament on Thursday, with the British and German leaders.

He invited Berlin to join "the expert review of the bill" and Britain's Prime Minister Keir Starmer suggested involving experts in scrutinizing the bill, Zelensky said in a statement after their phone call.

Zelensky's deputy prime minister in charge of Ukraine's EU integration, Taras Kachka, reassured the bloc's ambassadors that the independence of anti-corruption bodies remained a "priority".

But a solution that would satisfy all parties was needed, 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.

The law in question was swiftly approved by the parliament and signed by Zelensky on the same day.

It 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.