Officials say mammoth task underway despite lack of control of frontier in Donetsk region.
Russia's War Against Ukraine
Ukraine Today: Great wall of Ukraine – Russian border fortification less than 10 percent built (VIDEO)
A Ukrainian border guard looks through binoculars on July 2, 2015 as he controls the barbed wire fence on the Senkivka border post, around 200 kilometres (125 miles) north of the Ukrainian capital Kyiv.
