Kiev and its Western backers accuse Moscow of backing a pro-Russian separatist revolt in eastern Ukraine by providing troops and arms.
Russia continously denies the charges but says it has a right to defend the interests of the region's Russian-speaking majority.
The Kremlin has said Putin and Poroshenko may hold talks on the sidelines of a summit of Asian and European leaders in Milan on Oct. 16-17.
"I don't expect the talks will be easy. I'm used to this, I have a lot of experience of conducting very difficult diplomatic talks. But I'm an optimist," Interfax Ukraine news agency quoted Poroshenko as telling reporters.
Poroshenko said some European leaders might also join his talks with Putin.
Kremlin aide Yuri Ushakov has said a "Normandy-style meeting" could not be ruled out - a reference to talks in France in June involving Putin, Poroshenko and the leaders of Germany and France.
"The key and main question is peace. Russia's role in the issue of providing peace, as you understand, is difficult to overestimate," Poroshenko said.
"And today we raise the issue of moving from declarations to concrete steps."
Putin and Poroshenko are known so far to have met twice since the Ukrainian leader's election in May, firstly in Normandy and then in the Belarussian capital Minsk in August when they agreed on the need for a ceasefire between Kiev's forces and the pro-Russian rebels in eastern Ukraine.
GAS DEAL EYED
A ceasefire began on Sept. 5 and has broadly held despite frequent violations, especially around the airport of Donetsk, the biggest city of eastern Ukraine.
The European Union and the United States have imposed economic sanctions against Russia over the conflict in Ukraine, where Moscow has also annexed the Crimea peninsula.
In retaliation, Russia has banned most Western food imports.
The United Nations said on Wednesday the death toll from the conflict in eastern Ukraine now stood at more than 3,660 people.
Poroshenko also said on Saturday he hoped to make "significant progress" in Milan on resolving Ukraine's long-running gas pricing dispute with Russia.
Russia shut off gas deliveries to Ukraine in June over what it said were more than $5 billion in unpaid bills and Ukraine faces a possibility of energy shortages this winter if no deal is reached, risking a replay of the disruptions to Europe's gas supplies seen in 2006 and 2009.
"We believe that Ukraine's proposals are absolutely clear, concrete and justified. We are sure that we are significantly closer to solving this issue," he told reporters.
Separately, Russian Foreign Minister Sergei Lavrov and U.S. Secretary of State John Kerry are expected to discuss the situation in Ukraine at a meeting in Paris on Oct. 14.
Poroshenko, whose country holds parliamentary elections later this month, has faced some domestic criticism over elements of a peace plan agreed with Russia, especially his offer of autonomy to rebel-held regions of eastern Ukraine.
Interfax reported late on Friday that Poroshenko had sacked one of those critics, Serhiy Taruta, a billionaire businessman, as governor of the Donetsk region.
Poroshenko has appointed in Taruta's place as governor Oleksander Kikhtenko, a former head of interior ministry forces, Interfax said.
Source: Google News