Ukrainian President Petro Poroshenko has said he had support for a peace plan from leaders who attended a summit meeting in Minsk, including Russian President Vladimir Putin, the Interfax news agency reported.

But there were no indications that would mean an immediate end to the fighting in eastern Ukraine between pro-Russia separatists and Ukrainian forces in which about 2,000 civilians and more than 700 Ukrainian troops have died.

Putin said separately he had an "overall positive assessment" of Tuesday's meetings, which included face-to-face talks with Poroshenko.

Putin told reporters there was no discussion of a ceasefire in Ukraine because Russia was not a party to the conflict. Moscow is accused by Kiev and the West of arming and supporting the rebels a charge the Kremlin denies.

In addition to their one-on-one meeting, Putin and Poroshenko also met in a general session meeting with the presidents of Kazakhstan and Belarus, and top European Union officials.

The meeting in the capital of Belarus came on a day when Ukraine claimed it had captured 10 Russian soldiers who had come over the border.

I can say that the logic of this peaceful plan was finally supported by all, without exclusion, of the heads of state Petro Poroshenko, Ukrainian President

Putin did not directly address the allegation, but appeared to tacitly recognise it and suggested that the soldiers simply had lost their way.

"Ukrainian soldiers have found themselves on our side, too," he told reporters.

The fighting in eastern Ukraine also had expanded to a new front. The area around the city of Novoazovsk, strategically positioned on roads linking Russia with Crimea, which Moscow annexed in March, has come under heavy artillery firing in the past two days.

Shortly after Poroshenko took office in June, he released a peace plan for the conflict that included an amnesty for those not accused of serious crimes and called for some decentralisation of power to the region.

"I can say that the logic of this peaceful plan was finally supported by all, without exclusion, of the heads of state," Interfax quoted him as saying.

Getting the rebels to accept the plan, however, would be a key issue, and Russia appears either unable or unwilling to exert influence on the separatists to end their fight.

'Fate of Europe'

Kiev and many Western countries have repeatedly accused Moscow of providing arms and expertise to the pro-Russian rebels to try to destabilise Ukraine, something Russia has denied.

Poroshenko is under pressure to seek a negotiated settlement and not a military victory. He said the purpose of his visit was to start searching for a political compromise and promised that the interests of Russian-speakers in eastern Ukraine would be taken into account.

"The fate of peace and the fate of Europe are being decided in Minsk today," Poroshenko said in his opening remarks.

In his opening statement, Putin argued that Ukraine's decision to sign an association agreement with the 28-nation EU would lead to huge losses for Russia, which would then be forced to protect its economy. Russia had been counting on Ukraine joining a rival economic union it is forming with Belarus and Kazakhstan.

Ukraine is set to ratify the EU association agreement in September.

Ukraine wants the rebels to hand back the territory they have captured in eastern Ukraine, while Putin wants to retain some sort of leverage over the mostly Russian-speaking region so Ukraine does not join NATO or the European Union.

Russia has called frequently for Ukraine to federalise - devolving wide powers to the regions from the central government in Kiev. Poroshenko has resisted that move but he could agree to give the regions some expanded powers.