Russia "can only help to create an atmosphere of trust for this important and necessary process," Putin said. "We in Russia cannot talk about any conditions for the cease-fire, about any agreements between Kiev, Donetsk, Luhansk," the two rebel regions.
Although Poroshenko told reporters that he had secured support for a peace plan from leaders who attended the summit and Putin called the sessions "overall positive," the first substantial encounter between the two leaders did not produce a breakthrough in efforts to end the fighting.
If anything, there were signs of spreading violence. For the past two days, heavy shelling hit an area of southeast Ukraine that had escaped the intense fighting of recent weeks, and Ukrainian officials said the pro-Russia separatists it has been battling were aiming to open a new front.
The meeting in the Belarusian capital of Minsk also came on the same day that Ukraine said it captured 10 Russian soldiers who had come over the border.
Putin did not directly address the allegation but appeared to tacitly recognize it and suggested that the soldiers simply had become lost.
"I haven't received a report from the defense ministry and the general staff yet, but the first thing I have heard is that they were patrolling the border and may have found themselves on the Ukrainian territory," Putin said.
Shortly after becoming president in June, Poroshenko put forth a peace plan that included an amnesty for those not accused of serious crimes and called for some decentralization of power to the region. Early Wednesday, he said "I can say that the logic of this peaceful plan was finally supported by all, without exclusion, of the heads of state," according to the Interfax news agency.
But Putin said there was no specific talk about implementing a cease-fire because Russia is not a party to the conflict. Moscow is accused by Kiev and the West of arming and supporting the rebels.
Putin and Poroshenko also met Tuesday with the presidents of Kazakhstan and Belarus and top European Union officials. The presence of the other two presidents highlighted one of the difficult issues of Ukraine-Russia tensions: Their countries are part of a trade bloc with Russia, and Moscow fears that Poroshenko's pursuit of closer ties with the E.U. will hurt Russia's economy.
Controversy over whether Ukraine would join the trade bloc was at the heart of the events that set off Ukraine's crisis.