"Law enforcement agencies regularly report - the Minister of Internal Affairs, the Prosecutor General. They are investigating the circumstances of the murder of Andriy Parubiy," Zelensky said on the Telegram platform.

"Many forces are involved - all the necessary ones. The crime was unfortunately carefully prepared. But everything is being done to uncover this crime," the president said in a video message.

Zelensky indicated that he had also spoken with SBU head Vasily Maluks.

"The SBU is involved in the investigation," the president said.

Zelensky has ordered that verified information be provided to the public without delay.

It has already been reported that former Ukrainian parliament speaker Parubiy was shot dead in Lviv, western Ukraine, on Saturday. The killer has fled, and a massive search operation has been launched for him.

Parubiy was a member of parliament for several terms. He held the position of speaker from 2016 to 2019. In the 2019 elections, Parubiy was elected to parliament from the list of former president Petro Poroshenko's"European Solidarity" party.

With the murder of Parubiy, the enemies are trying to sow fear, Kirill Budanov, head of the Main Intelligence Directorate (HUR) of the Ministry of Defense of Ukraine, said on the Telegram platform.

"The enemies are unable to conquer Ukraine by force, so they resort to terrorism, trying to sow fear, provoke tension and chaos in society in order to break the will of the Ukrainian people to resist," the head of HUR explained.

Budanov expressed his deepest condolences to Parubiy's family and friends.

"He will forever remain an example of loyalty to the Ukrainian cause and the unity of the Ukrainian people," the intelligence chief said in a message.