The presidents of Russia and Ukraine sat down for talks Tuesday, meeting face to face for the first time since June about the fighting that has engulfed Ukraine's separatist east.
Russia's Vladimir Putin and Ukraine's Petro Poroshenko were joined by the presidents of Belarus and Kazakhstan, as well as three senior officials from the European Union, in the Belarusian capital city of Minsk.
"The fate of peace and the fate of Europe are being decided in Minsk today," Poroshenko said as the talks began.
Under pressure to seek a negotiated settlement and not a military victory, the Ukrainian president said the purpose of his visit was to start the process of searching for a political compromise. He promised that the interests of Russian-speaking eastern Ukraine would be taken into account.
"We are convinced that today, (the Ukraine crisis) cannot be solved by further escalation of the military scenario, without taking into account vital interests of the southeastern regions of the country and without a peaceful dialogue with its representatives," Putin said.
But Putin, for his part, devoted most of his opening remarks to trade, arguing that Ukraine's decision to sign an association agreement with the 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 that it is forming with Belarus and Kazakhstan.
Putin also said the Russian economy could suffer a loss of some $2.77 billion if EU goods reach Russia via Ukraine, bypassing the tariffs Russia levies on EU goods.
"Russia cannot remain idle in such a case and we will simply be forced to take decisive measures to protect our market," he said, adding that such measures would include reversing trade preferences for imports from Ukraine.
The meeting came only hours after Ukraine released video footage on Tuesday of what it said were Russian soldiers captured on its territory.
Tuesday's video provided the strongest evidence yet to back up Kiev's claims that Russia has been sending arms and troops across the border to support pro-Russia rebels.
Russia has always denied such assertions by Ukraine. In response to the latest incident — in which Ukraine’s state security service said it had detained 10 Russian paratroopers who had crossed the border in a column of several dozen armed infantry vehicles — a military source told Russian news agencies that a group of soldiers had surrendered to Ukrainian forces after accidentally crossing the border.
“The soldiers really did participate in a patrol of a section of the Russian-Ukrainian border, crossed it by accident on an unmarked section, and as far as we understand showed no resistance to the armed forces of Ukraine when they were detained,” the source said.
The capture took place near the Ukrainian village of Dzerkalne, which is located about 12 to 19 miles from the border with Russia and about 31 miles southeast of the rebel hub Donetsk.
The United States also warned of a significant escalation in the conflict between the two countries.
"Repeated Russian incursions into Ukraine unacceptable. Dangerous and inflammatory," U.S. National Security Adviser Susan Rice said on Twitter late Monday.
In footage posted on the official Facebook page of the Ukrainian government's "anti-terrorist operation," the men were shown dressed in camouflage fatigues.
Russia reportedly has tens of thousands of troops positioned in areas near the Ukrainian border, leading to persistent concerns that Russia could be preparing for an invasion.
Pro-Russia rebels have been fighting Ukraine's army since April in a war that has killed over 2,000 people and triggered Western sanctions against Russia.