The president's comment was made during his meeting with President of Malta Marie-Louise Coleiro Preca, 112 Ukraine TV channel reports.
"I believe that peaceful manifestations are an important element of democracy, and I understand and respect their participants," said Poroshenko.
The president has also demanded that the law enforcement agencies ensure the peaceful nature of protests.
No one can allow irresponsible politicians to repeat the tragic events that took place on August 31, which resulted in the death of four national guardsmen," the president said.
Read alsoUnprecedented security measures in Kyiv as number of political forces hold rallyPoroshenko has added that ensuring public order is an important task for both law enforcers and organizers of protests.
As reported earlier, today the leaders of several political parties and public organizations announced a large-scale rally in support of Ukraine's political reform. Behind the rally stand the "Rukh [Movement] of the New Forces" of Mikheil Saakashvili, Alternativa, "Demaliance", Chesno NGO, Yulia Tymoshenko's Batkivshchyna, Samopomich, and other organizations.