Russian President Vladimir Putin told German Chancellor Angela Merkel on Friday that further delays in delivering humanitarian aid into eastern Ukraine would have been unacceptable, the Kremlin said in a statement.
In a phone call initiated by the German leader, Putin said that following "clear procrastination" by Kiev, Russia decided to begin the controversial mission because "further delays would have been unacceptable" given the humanitarian catastrophe in the conflict zone, the Kremlin said.
After a week-long delay at the border, a Russian convoy of 280 trucks carrying 1,800 tonnes of humanitarian aid according to Moscow rolled Friday into Ukraine without being inspected by Ukrainian authorities or accompanied by the Red Cross.
Kiev called the action an invasion and the EU a "clear violation" of Ukraine's border.
The Russian foreign ministry rebuffed accusations that Moscow had violated international law. "We are acting in full accordance with the norms of international humanitarian law," Deputy Foreign Minister Sergei Ryabkov said in a statement. He alleged that Kiev had wanted to block the delivery of the aid while it tried to achieve a military victory.
"It was Kiev, clearly backed by its Western supporters, who did everything to derail this important humanitarian action," said Ryabkov.
"The Ukrainian authorities needed time to try to complete the military operation to suppress the protest of its own people, spilling blood and tears where Russian humanitarian aid is now being distribution," he said. "They didn't succeed."
Local officials confirmed the convoy had arrived in Lugansk on Friday.
Fighting between Ukrainian government forces and pro-Russian rebels has recently grown more deadly around Lugansk, the decimated former home to nearly 420,000 mostly Russian-speakers. Many have fled due to a dire lack of food, water and medicine.