Ukrainian soldiers are reinforcing positions in areas recently reclaimed from pro-Russian separatists in eastern Ukraine.
With the help of high-tech gadgetry and brute force, government officers say they have claimed the upper hand, but on the front lines of the conflict it appears outright victory for Kyiv's army will not be easy. Aid agencies say thousands of civilians caught in the crossfire are living without electricity, water and basic supplies, and soldiers at a checkpoint in Debaltseve, deep in Donetsk province, say the pro-Russian rebels who have retreated are well-equipped.
Ukrainian forces and pro-Russian separatists skirmished repeatedly near the Russian border Saturday but there was no sign of the conflict widening a day after Kyiv said it partially destroyed an armored column that had crossed the border from Russia.
The report of the attack on the column Friday triggered a sell-off in the U.S. dollar and on European stocks, with markets fearful it could change the Ukraine conflict into an open confrontation between Moscow and Western-backed Kyiv.
But Moscow made no threat of retaliation, instead saying it was a “fantasy” that its armored vehicles entered Ukraine. In Washington the White House said it could not confirm that Russian vehicles had been attacked on Ukrainian soil.
Meanwhile, nearly 300 trucks in a Russian aid convoy remained idled near the Ukrainian border outside the Russian town of Kamensk-Shakhtinsky, as complicated procedures drag on for allowing them into eastern Ukraine to help civilians suffering amid fighting.
The International Committee of the Red Cross (ICRC) would then have the responsibility for distributing the aid to Ukrainians caught in the middle of the conflict with Ukrainian forces and separatists.
On Saturday, the head of the ICRC delegation for Russia, Pascal Cuttat, said Moscow and Kyiv have agreed on how to proceed in terms of clearing, inspecting and preparing the goods. He noted the security guarantees were needed from all sides before the trucks could move. Ukrainian officials say they have begun inspecting the aid convoy.
Moscow says the mission is purely humanitarian, but Kyiv and the West have voiced concerns it could serve as a "Trojan Horse" for an invasion or a way to re-arm pro-Russian rebels who have suffered previous losses.
Earlier Saturday, U.S. Vice President Joe Biden spoke with Ukrainian President Petro Poroshenko to discuss the situation in Ukraine. The White House says both leaders reaffirmed their support for a diplomatic solution to the crisis and called on Russia to enter into good faith negotiations.
The foreign ministers of Russia, Ukraine, France, and Germany are expected to meet Sunday in Berlin to discuss the tensions in Ukraine.
German Foreign Minister Frank-Walter Steinmeier told Bild newspaper that he hopes the talks will help put an end to violence in eastern Ukraine and help provide residents of the war-torn region with humanitarian aid.
French President Francois Hollande and European Commission President Jose Manuel Barroso discussed the situation Saturday. Afterward, Hollande called on Russia to respect Ukraine's territorial integrity and urged Kyiv to exercise restraint in its military activities. He said France is ready for a new summit on the issue and added that Sunday's meeting could be used as a first step toward that end.
Reports of ongoing skirmishes
On the ground Saturday, the conflict returned to the pattern it has been following for several weeks. Kyiv said military equipment was entering from Russia, and the rebels said they had attacked Ukrainian troops.
A Reuters reporter in Donetsk, one of two rebel strongholds in the east, said the sound of explosions was audible in the city center.
Finnish President Sauli Niinisto was to arrive in Kyiv later Saturday for talks with his Ukrainian counterpart, Petro Poroshenko, aimed at finding a negotiated solution. Niinisto met Russian President Vladimir Putin on Friday and afterwards spoke of the possibility of a truce, although it was not immediately clear how that would happen.
Moscow and Kyiv counter-claims
The conflict has dragged relations between Russia and the West to their worst since the Cold War and set off a round of trade restrictions that are hurting struggling economies both in Russia and Europe.
An estimated 2,090 people had died in the Ukraine conflict, with nearly 5,000 wounded, the United Nations said this week.
A rebel Internet news site said Saturday that separatist fighters had killed 30 members of a Ukrainian battalion in fighting in Luhansk province, a rebel-held area adjacent to the Russian border.
Rebels said two villages south of Donetsk, the other separatist stronghold, were bombed overnight with mortars. Rebel news outlet Novorossiya also said two neighborhoods itself had been hit with artillery.
A top Ukrainian government spokesman, Andriy Lysenko, contradicted the assertions. He said three Ukrainian servicemen had been killed over the past 24 hours, and denied Kiev's forces were firing artillery on Donetsk.
In the past few hours, security forces had spotted Russian drones and a helicopter crossing illegally into Ukraine's airspace, Lysenko told a news briefing.
He declined to give further details on the incident on Friday in which Kiev said it attacked armored vehicles that arrived from Russia. Ukraine has not made clear if the vehicles were manned by Russian soldiers or separatist irregulars.
Ukrainian momentum
Ukraine and its Western allies say Russia broke international law by annexing Ukraine's Crimea peninsula earlier this year, and that Moscow is now arming the Ukrainian separatists. Russia accuses Kiev of waging a criminal war against Russian-speaking civilians in the east. Both sides reject the allegations.
After a string of early defeats, Ukrainian forces have pushed the separatists out of large swathes of territory and have now nearly encircled them in Donetsk and Luhansk. Kiev says it now controls the road linking the two cities.
Russia asserts the offensive is causing a humanitarian catastrophe for the civilian population in the two cities. It accuses Kiev's forces of indiscriminately using heavy weapons in residential areas, an allegation Ukraine denies.
The convoy of more than 250 trucks purportedly carrying humanitarian aid had traveled south from the Moscow region earlier this week, alarming Kyiv and Western backers who fear the trucks entering Ukraine without approval could be a pretext for an invasion.
Moscow and Kyiv had agreed that the trucks could enter with Red Cross accompaniment if Ukrainian border guards and customs agents approved the cargo. A representative of Russia's Emergencies Situations Ministry, who declined to give his name, told AP that documents about the cargo have been given to Ukrainian officials who have come to Donetsk for the cargo inspection.
The AP also reported that Kyiv had sent a smaller but substantial aid mission to parts of the east recently freed from rebel control.
Trucks sent from the city of Kharkiv were unloaded Friday at warehouses in Starobilsk, where the goods were to be sorted and transported further by the Red Cross. Starobilsk is 60 miles north of Luhansk.
Other Ukrainian aid was taken to Lysychansk, which retaken by Ukrainian forces late last month but has seen sporadic clashes, AP reported.
In the past week, three senior rebel leaders have been removed from their posts, pointing to mounting disagreement over how to turn the tide of the fighting back in their favor.
Lysenko said he had reports of rebel fighters abandoning their posts in Luhansk, and preparing to leave Donetsk and seek safe haven in Russia.
“A mood of panic is spreading and rebels are trying to leave through the small gaps that remain,” he said.
Alexander Zakharchenko, prime minister of the self-proclaimed Donetsk People's Republic, disupted that, saying reinforcements were on their way.
In a video posted on another rebel Internet site, he said these included 150 armored vehicles and 1,200 fighters who, he said, had spent four months undergoing training in Russia.
VOA correspondent Gabe Joselow contributed reporting from Debaltseve, Ukraine. Material from Reuters and The Associated Press was used in this report.