The president announced earlier this week his intention to declare a "unilateral ceasefire" to give pro-Russian armed separatists the opportunity to lay down their weapons and Russian mercenaries to depart Ukraine.
The armed separatists, however, roundly rejected the proposed ceasefire, insisting they "will not put our weapons away."
On Friday, Poroshenko traveled to the east and met with troops and residents in a town north of rebel-held Sloviansk.
"We will do everything to protect the territory of our state," the president insisted, noting that the declared ceasefire "doesn't mean we won't fight back against any aggression towards our troops."
The president is expected to present his peace plan at a European Union Foreign Affairs Council meeting in Luxembourg on June 23.