With a theatrical flourish, Russia on Tuesday dispatched hundreds of trucks covered in white tarps and sprinkled with holy water on a mission to deliver aid to a desperate rebel-held zone in eastern Ukraine.

The televised sight of the kilometres-long convoy sparked a show of indignation from the government in Kyiv, which insisted any aid must be delivered by the International Red Cross. Ukraine and the West have openly expressed its concern that Moscow intends to use the cover of a humanitarian operation to embark on a military incursion in support of pro-Russian separatists.

Amid those anxieties, Russian President Vladimir Putin on Wednesday was set to travel to Crimea, the Black Sea peninsula Russia annexed in March, where he was to preside over a meeting involving the entire Russian Cabinet and most members of the lower house of parliament.

Putin so far has resisted calls from both pro-Russian rebels in eastern Ukraine and nationalists at home to send Russian troops to back the mutiny, a move that would be certain to trigger devastating Western sanctions. But dispatching the convoy sent a powerful visual symbol helping the Kremlin counter criticism from the nationalists who accuse Putin of betrayal.

The convoy provoked controversy as soon as it started moving early Tuesday from the outskirts of Moscow on its long voyage toward the Ukrainian border.

Ukraine

A Ukrainian government soldier from the "Donbass" battalion guards a position in eastern Ukraine. Kyiv and the West have repeatedly opposed a Russian humanitarian aid mission to eastern Ukraine, fearing that such a move could preface an intervention by Moscow. (Evgeniy Maloletka/Associated Press)

Officials with both the International Committee of the Red Cross and Ukraine's government said they had no information about what the trucks were carrying or where they were headed.

From baby food to portable generators

A Ukrainian security spokesman said the convoy of white-canvased vehicles was being managed by the Russian army and could not as a result be allowed into the country. Moscow has rejected the claim, saying that the convoy is organized by the Emergencies Ministry, a non-military agency dealing with humanitarian relief tasks.

The government in Kyiv said the Russian trucks could unload their contents at the border and transfer the aid to vehicles leased by the ICRC.

U.S. State Department deputy spokeswoman Marie Harf said talks are under way for Russia to deliver the aid to the Ukrainian border where it would be transferred to the custody of the ICRC.

She said the U.S. has received confirmation from Ukraine that it is ready to facilitate the arrival of the aid and arrange for its delivery to Luhansk as long as certain conditions were met. Such conditions included that the aid passes appropriate customs clearances, that the ICRC takes custody and responsibility for the delivery in Ukraine, that the Russian-backed separatists allow safe access for the delivery and that the shipments are received at a border crossing point controlled by the Ukrainian government in the Kharkiv region. At least 100 kilometres of the long border between the two neighbours is currently in rebel hands.

Ukraine

Ukrainian troops have surrounded the rebel-held city of Donetsk and expect to retake it within the coming days. Russia is attempting to send humanitarian aid to citizens in Luhansk, the other major rebel stronghold in Ukraine's east. (Evgeniy Maloletka/Associated Press)

The U.S. supports the Ukrainian proposal, Harf said.

Russian authorities said the trucks were loaded with nearly 2,000 metric tons of cargo from baby food to portable generators. Television images showed a Russian Orthodox priest sprinkling holy water on the trucks, some of which bore a red cross, before they departed.

Foreign Minister Sergey Lavrov said Russia has bowed to Ukrainian demands that the convoy should enter its territory through a checkpoint designated by Kyiv, that Ukrainian number plates be put on trucks there and that Ukrainian representatives should be put on board the trucks alongside Red Cross staff.

Co-operation from separatists

However, he said that the idea to unload the trucks on the border and put the cargo on chartered vehicles had come under discussion, but had been rejected for cost reasons.

Valeriy Chaly, the deputy head of Ukraine's presidential administration, said a suitable transfer point could be between Russia's Belgorod region and Kharkiv, which has been spared the major unrest seen farther south. Chaly said that any attempt to take humanitarian goods into Ukraine without proper authorization would be viewed as an attack.

RUSSIA-UKRAINE-CRISIS/AID

A Russian convoy of trucks sets off from near Moscow amid Western warnings against using help as a pretext for an invasion. (Reuters TV/Reuters)

Ukraine has stressed that the effort to alleviate hardship in the conflict-wracked Luhansk region should be seen as an international undertaking. Officials in Kyiv have said Russia's involvement in the humanitarian mission is required to ensure co-operation from separatist rebel forces, who have consistently expressed their allegiance to Moscow.

French President Francois Hollande discussed the aid delivery Tuesday with Putin, saying "he emphasized the strong fears evoked by a unilateral Russian mission in Ukrainian territory." Hollande told Putin that any mission must be multilateral and have the agreement of the ICRC and Ukraine, according to a statement in Paris.

NATO was following the situation closely, spokeswoman Oana Lungescu said.

"Without the formal, express consent and authorization of the Ukrainian government, any humanitarian intervention would be unacceptable and illegal," she said.

The Western alliance also expressed concern about the possibility of a Russian military operation.

"What we see is thousands of combat-ready troops from Russia being close to the Ukrainian border," NATO spokeswoman Carmen Romero said. "There could be a risk of further intervention."