Ukrainian President Petro Poroshenko has said he does not rule out that the murder of Belarusian journalist Pavel Sheremet was carried out with the aim of destabilizing the situation in the country.

"I think it was done for one single reason – to destabilize the situation in Ukraine, perhaps, ahead of other events," Poroshenko said at a meeting of law-enforcement agency heads on Wednesday.

The president tasked law-enforcement agencies with investigating the murder as comprehensively and quickly as possible.

"Don't omit any version. I want to ask everyone in these conditions, in these conditions of war and aggression … and I also don't rule out the involvement of foreign interests [in the murder]," Poroshenko said.

The president said the authorities and society must now come together in order show those who ordered the killing that the murder will not achieve their goal.