Russia's emergency services ministry has dispatched a 280-truck convoy said to be carrying humanitarian aid to eastern Ukraine - but officials in Kiev warned that Russian military vehicles and personnel won't be allowed through the border.
The International Committee of the Red Cross also warned Moscow that it had yet to receive details of the convoy's contents, its travel route or how it intends the 2000 tons of food, water, medicine and other essentials to be distributed to those in need in separatist-held Luhansk.
Russian President Vladimir Putin has been pushing for weeks to send in relief supplies for the Russian-speaking communities in Luhansk and Donetsk, the last strongholds of a pro-Russia insurgency that has killed more than 1,200 people on the ground and 298 in the downing of a Malaysian passenger jet.
Ukrainian officials had previously rejected Moscow's insistence on sending aid into the two eastern Ukraine redoubts of the flagging separatist uprising, fearing the Kremlin would use the massive convoy to funnel in arms and fighters to revive the anti-Kiev rebellion.
As Putin and other Kremlin officials have been drumming up international support for a relief operation in the embattled eastern regions, Ukrainian and NATO officials have warned of a massive Russian troop buildup on the border. NATO Secretary-General Anders Fogh Rasmussen on Monday said he considered a Russian invasion a "high probability," escalating Ukrainian wariness that the aid convoy could be a Trojan horse carrying military supplies to the insurgents.
"We are not considering any movement of Russian columns through Ukrainian territory," Valeriy Chaly, deputy head of Ukrainian President Petro Poroshenko's administration, told reporters at a press conference in Kiev. He said only trucks owned or leased by the Red Cross would be permitted to carry aid to the separatist-held regions and that the convoy must enter Ukraine through a government-controlled border crossing.
Any attempt by Russian vehicles or personnel to enter Ukraine without Red Cross inspection and the Kiev government's approval will be regarded as "an act of aggression," Chaly said.
After more than four months of fighting between Ukrainian government forces and separatists bent on annexing strategic eastern Ukraine territory to Russia, water and electricity systems in Luhansk have been badly damaged and food, fuel and medical supplies to the city have been disrupted.
More than half of Luhansk's 465,000 population has fled, but the more than 200,000 still hunkered down in the city have been without water, power or communications for weeks.
The Russian Emergencies Ministry sent the convoy rolling from Moscow after a ceremonial blessing by a Russian Orthodox priest and broad coverage of the event by state-run media.
Russia's RIA Novosti agency said the miles-long convoy was expected to reach the border near the Ukrainian city of Kharkiv on Wednesday (local time) after the 725km journey.
Itar-Tass news agency said the trucks were carrying 2000 tons of aid, including water, cereal, sugar, baby food, medicine and medical equipment, sleeping bags and generators.
Poroshenko agreed to the aid delivery Monday after consultation with European Union leaders and President Barack Obama and on condition that the Red Cross and Western governments were involved in an "international operation."
But Laurent Corbaz, head of Red Cross operations for Europe and Central Asia, said the Swiss-based relief agency was still waiting for a detailed manifest from Russian authorities as well as security assurances from both sides in the conflict.
"We are in constant contact with both the Ukrainian and Russian authorities on this. They know what are our requirements. We are waiting for their feedback," Corbaz said.
-Los Angeles Times