Ukrainian border guards and customs officials on Friday began inspecting a Russian humanitarian aid cargo for eastern Ukraine at a border point inside Russia, a Ukrainian military statement said.
A convoy of 280 Russian trucks brought the aid to the border in an operation which aroused Kiev's suspicions that it might be used as a cover for a military operation in Ukraine.
Moscow has denied any ulterior motives, but has allowed Ukrainian border guards to enter Russia and inspect the caravan of trucks in an area opposite the frontier town of Izvaryne.
"Ukrainian border guards are there already in large numbers," border guard spokesman Andriy Demchenko said.
The Ukrainian military said the inspection began on Friday morning, but it was not clear how long the process might take.
Russian media also said Russian and Western journalists had been allowed to participate in the inspection, including reporters from Reuters, Bloomberg, Associated Press, Agence France Press and the BBC, Lenta.ru reported.
Material from the Moscow Times was included in this report.