MOSCOW -- A convoy of 280 Russian trucks reportedly packed with aid headed for eastern Ukraine on Tuesday, but Kiev said it would only allow the goods through under the close supervision of the international Red Cross.
A Ukrainian security spokesman said the convoy of vehicles was being managed by the Russian army and that it could not be allowed into the country.
The humanitarian crisis provoked by fighting between government troops and pro-Russian separatist militants in eastern Ukraine has reached a critical point in recent days and heightened the urgent need for intervention.
But Ukraine and the West have voiced concerns that Russia could use the aid initiative as a cover for sending troops into separatist-held territory.
"This convoy is not a certified convoy. It is not certified by the International Committee of the Red Cross," said Andriy Lysenko, a spokesman for Ukraine's National Security and Defense Council. "No military structures have the right to escort humanitarian aid convoys, especially into another state."
The government in Ukraine says it is willing for trucks from Russia to unload their contents at the border and for the aid to be transferred to transportation leased by the ICRC.
Officials with the ICRC and Ukraine's government said Tuesday they had no information on what the trucks were carrying or where specifically they were headed.
The Ukrainian government has insisted that aid must cross at a government-held border crossing. At least 100 kilometers (60 miles) of the border is currently in rebel hands.
Valeriy Chaly, the deputy head of Ukraine's presidential administration, said a suitable transfer point could be between Russia's Belgorod region and Ukraine's Kharkiv region, which has been spared the major unrest seen further south.
Chaly said that any attempt to take humanitarian goods into Ukraine without proper authorization would be viewed as an attack on the country.
Alexander Drobyshevsky, a spokesman for Russia's emergency ministry that is conducting the mission, told the AP that his organization had "not yet defined" where the trucks would cross the border. He said it could take several days for them to reach Ukraine.
Ukraine has stressed that the aid effort to alleviate hardship in the conflict-wracked Luhansk province in the east should be seen as an international undertaking. Officials in Kiev have said Russia's involvement in the humanitarian mission is required to ensure cooperation from separatist rebel forces, who have consistently expressed their allegiance to Moscow.
Russian television and news agencies reported Tuesday that 2,000 tons of aid was en route to Ukraine.
Pro-Kremlin television channel NTV showed hundreds of white trucks gathered at a depot outside Moscow, and said they were carrying everything from baby food to sleeping bags. The report showed a Russian Orthodox priest sprinkling holy water on the trucks, some of which bore a red cross, before their departure.
But Lysenko said suspicions have been raised by the military provenance of the trucks in the convoy. In a briefing, he showed a covertly filmed video appearing to show vehicles similar to the white-canopied trucks parked at a military base in Russia.
One frame in the video displayed by Lysenko shows uniformed troops lined up in front of one the trucks.
Andre Loersch, a spokesman for the ICRC mission in Ukraine, said that while the organization had reached a general agreement about delivery of humanitarian aid to the region, he had "no information about the content" of the trucks and did not know where they were headed.
"At this stage we have no agreement on this, and it looks like the initiative of the Russian Federation," he said.
French President Francois Hollande discussed the aid delivery with Russian President Vladimir Putin, saying "he emphasized the strong fears evoked by a unilateral Russian mission in Ukrainian territory."
Hollande told Putin Tuesday morning that any mission must be multilateral and have the agreement of the ICRC and Ukraine, according to a statement in Paris.
Some of the heaviest impact on civilians from fighting has been seen in Luhansk -- the rebel-held capital of the Luhansk province that had a prewar population of 420,000. In a status update Tuesday, city authorities said the 250,000 residents remaining had had no electricity or water supplies for 10 days.
"Luhansk is under a de facto blockade: The city continues to be destroyed, and the delivery of foodstuffs, medicine and fuel has been interrupted," the city council said in the statement.
A large portion of the Russian border with Luhansk province is under separatist control.
Throughout the conflict, Ukraine and the West have accused Russia of aiding the rebels with arms and expertise, a charge that the Kremlin has denied.
Peter Leonard in Kiev, Ukraine, and Lori Hinnant in Paris contributed to this report.