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.Speaking to reporters 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 may be announced in "hours or days" but gave no details."The peace plan begins with my order for a unilateral ceasefire," Interfax-Ukraine quoted the president as saying."Immediately after that, we must receive support for the presidential peace plan from all sides involved. This should happen very shortly."The Kremlin confirmed that Mr Poroshenko and Mr Putin "touched upon" the issue of a possible ceasefire during their talks on Tuesday.(BBC)ANN.Az