All 227 vehicles that entered Ukraine as part of a Russian aid convoy have now returned to Russian soil, security watchdog the Organisation for Security and Cooperation in Europe (OSCE) said on Saturday.
The Vienna-based OSCE said in a statement the vehicles were counted back in to Russia from Ukraine by its observer mission deployed at a border crossing.
Trucks from a Russian aid convoy started crossing back into Russia on Saturday after igniting a storm of anger in Western capitals a day earlier by driving into Ukraine without the permission of the government in Kiev.
The return of the trucks may help ease the tension to some extent in time for the arrival of German Chancellor Angela Merkel in the Ukrainian capital later on Saturday for talks on how to end the crisis over Ukraine.
Western leaders had joined Kiev in calling the Russian convoy -- about 220 white-painted trucks loaded with tinned food and bottle water -- an illegal incursion onto Ukraine's soil, and demanded that they be withdrawn as soon as possible.
Russian state television had earlier broadcast footage of some of the trucks being unloaded at a distribution depot in the city of Luhansk, eastern Ukraine.
The city is held by separatist rebels who are encircled by Ukrainian government forces, and has been cut off from power and water supplies for weeks. International aid agencies have warned of a humanitarian crisis.
NATO said it had evidence that Russian troops had been firing artillery at Kiev's forces inside Ukraine - fuelling Western allegations that the Kremlin is behind the conflict in an effort undermine the Western-leaning leadership in Kiev.
The White House made the same allegation. "We have seen the use of Russian artillery in Ukraine in the past days," said U.S. deputy national security advisor Ben Rhodes.
Russia denies giving any material help to the rebellion in eastern Ukraine, a mainly Russian-speaking region. It accuses Kiev, with the backing of the West, of waging a war against innocent civilians.
The conflict in Ukraine has dragged Russian-Western relations to their lowest ebb since the Cold War and sparked a round of trade sanctions that are hurting already-fragile economies in European and Russia.
In the rebels biggest strong hold, the city of Donetsk, there was unusually intense shelling on Saturday. That may be part of a drive by government forces to achieve a breakthrough in time for Ukrainian Independence Day, which falls on Sunday.
The crisis over Ukraine started when mass protests in Kiev ousted a president who was close to Moscow, and instead installed leaders viewed with suspicion by the Kremlin.