KYIV, Sept 23 - Ukraine has begun a large military exercise in response to the Caucasus-2020 drills in neighbouring Russia, aiming to show the preparedness of its army to repel any attack from Russian soil, Reuters reported Wednesday citing the Ukrainian military.

Relations between Russia, which began its strategic command and staff exercises on Monday, and Ukraine - both ex-Soviet republics - soured in 2014 when Moscow annexed the Crimea peninsula from its neighbour.