Ukraine’s president has proposed a unilateral ceasefire by his troops to allow pro-Russian separatists to lay down their weapons.
Petro Poroshenko said the peace plan would be implemented “shortly”, Interfax-Ukraine news agency reports.
His announcement comes after he held a phone conversation with Russian President Vladimir Putin.
They discussed a solution to the crisis in eastern Ukraine, where pro-Russian rebels are battling government forces.
More than 30 gunmen were killed and wounded in fighting near the town of Schastya in the Luhansk region on Tuesday, a spokesman for the government’s “anti-terrorism operation” said.
Meanwhile Ukraine’s Interior Minister Arsen Avakov has said an explosion at a major pipeline in central Ukraine was caused by a bomb.
He said explosives had been placed under a concrete support at the Urengoy-Pomary-Uzhgorod Pipeline.
No-one was reported injured by the blast. European and Russian companies said gas exports were not affected by Tuesday’s pipeline explosion.
Speaking at a graduation ceremony at the National University of Defence in Kiev, Mr Poroshenko said a “brief” truce would be introduced to allow “Russian mercenaries” to leave Ukraine.
A presidential spokesman told the BBC the ceasefire could be announced in “hours or days” but gave no further details.
The Kremlin confirmed that Mr Poroshenko and Mr Putin “touched upon” the issue of a possible ceasefire during their talks on Tuesday.
Correspondents say Mr Poroshenko has made similar comments in the past but it is not clear when the ceasefire will be implemented.
“The peace plan begins with my order for a unilateral ceasefire,” Interfax-Ukraine quoted the president as saying on Wednesday.
“Immediately after that, we must receive support for the presidential peace plan from all sides involved. This should happen very shortly.”
He said Russia was waging “a new type of warfare” with the use of professional subversive groups and volunteers.
Russia says it has launched a criminal investigation into Ukraine’s interior minister and a local governor over the killings of civilians and journalists.
Mr Avakov and Igor Kolomoisky, governor of Dnipropetrovsk, are accused of organising military operations, including rocket strikes, in cities such as Donetsk, Sloviansk and Mariupol that left more than 100 dead, Russian state media said.
