MINSK, Belarus -- Ukraine's president said Wednesday that Vladimir Putin accepts the principles of a peace plan for Ukraine but the Russian leader insisted that only Kiev can reach a cease-fire deal with the pro-Moscow separatists.
Following meetings between Putin and Ukrainian President Petro Poroshenko that included a one-on-one session that stretched into the night, there was no indication of a quick end to the fighting that has engulfed eastern Ukraine.
"This is not our business," Putin said of any cease-fire plan. "This is Ukraine's business."
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, 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 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.
However, 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 -- a charge the Kremlin denies -- and it is not clear how much it is willing or able to try to pressure them into ending the fighting.
Besides their face-to-face talks, 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 determination to pursue closer ties with the EU 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. Former president Viktor Yanukovych's decision to pursue closer ties with Russia set off protests that eventually drove him from power. After his ouster, the Crimean peninsula, overwhelmingly ethnic Russian, was annexed by Moscow in March and the next month saw the beginning of a separatist rebellion in two eastern Ukrainian regions that are heavily ethnic Russian.
The battle to put down that rebellion, which Kiev and Western countries say gets equipment, fighters and other support from Russia, has left more than 2,000 civilians and 700 Ukrainian troops dead.
In his opening statement at Tuesday's meetings, 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.
Putin also said the conflict "could not be solved by further escalation of the military scenario without taking into account the vital interests of the southeast of the country and without a peaceful dialogue of its representatives."
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 federalize -- 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. Poroshenko also has spoken against holding a referendum on Ukraine's joining NATO.
Putin has so far ignored requests from the rebels to be annexed by Russia, unlike in March, when he annexed Ukraine's Crimean Peninsula. But Associated Press journalists on the border have seen the rebels with a wide range of unmarked military equipment -- including tanks, Buk missile launchers and armored personnel carriers -- and have run into many Russians among the rebel fighters.
Ukraine's anti-rebel operation said on its Facebook page that 10 soldiers from a Russian paratrooper division were captured Monday around Amvrosiivka, a town near the Russian border.
Ukraine's posting included videos of five of the men. One, who identified himself as Sergei Smirnov, said they were not told anything about their mission.
"We were just traveling through fields and then we stopped in the middle of the field and the BMP2 (armored vehicle) broke down," he said.
Asked if he knew they were on Ukrainian territory, he said: "When we got into the village we saw a tank with Ukrainian flag. Then we understood." He said they then came under fire.
Russian news agencies quoted an unidentified official in the Russian Defense Ministry as saying the soldiers were patrolling the border and probably crossed it inadvertently.
Meanwhile, towering columns of smoke rose Tuesday from outside a city in Ukraine's far southeast after what residents said was a heavy artillery barrage, and Ukraine accused the separatists and Russia of trying to expand the conflict.
It was the second straight day that attacks were reported in the vicinity of Novoazovsk, which is in eastern Ukraine's separatist Donetsk region but previously had seen little fighting.
Novoazovsk lies on the Azov Sea on the road that runs from Russia to the major Ukrainian port of Mariupol and west to Crimea, the Black Sea peninsula annexed by Russia.
Ukraine said a small column of Russian tanks and armored vehicles crossed into Ukraine on Monday north of Novoazovsk, raising the possibility that pro-Russia separatists were aiming to take control of a strip of land that would link up Russia with Crimea.
In Kiev, Col. Andriy Lysenko, a spokesman for Ukraine's National Security Council, blamed the shelling Tuesday on "Russian mercenaries."
"Russia is trying from its side to open a new front," Lysenko told reporters.
Residents in Novoazovsk, some hastily packing up in order to flee, told the AP it was not clear what direction the firing had come from Tuesday.
Lysenko said there were enough forces and equipment in Mariupol to defend the city of more than 450,000. Russia reportedly has tens of thousands of troops positioned in areas near the Ukrainian border, leading to persistent concerns that Moscow could be preparing an invasion.