NATO member Lithuania has delivered Ukraine more than 150 tons of munition to aid it in the battle against pro-Russian separatists.
The delivery consisted mostly of cartridges for AK-47 assault rifles, military spokesman Tomas Pakalniskis told the news agency BNS on Saturday.
The Lithuanian army didn't need the ammunition, he said, because it doesn't meet NATO standards.
In 2015 Lithuania rejected Russian complains that its previous supply of lethal weaponry to Ukraine violated international arms trade commitments.
The Baltic states - Estonia, Latvia and Lithuania - are the geographically closest NATO members to Russia and have been fearful of a potential Russian invasion since their former Soviet ruler annexed Ukraine's southern Crimea region two years ago.
Tensions have been high after the military alliance held training missions in Eastern Europe this summer, saying it plans to deploy more soldiers in the region in the future.
Russia responded saying it will deploy 10,000 more contract soldiers to the western part of the country.
Russia is deploying long-range S-400 missile systems in Crimea amid heightened tensions with Ukraine, Russian state news agency TASS reported Friday.
Russia is deploying 10,000 more contract soldiers to the western part of the country as the situation there is unstable, Defence Minister Sergei Shoigu said Wednesday.
As relations between NATO and Russia continue to sour in the wake of the Ukraine crisis, some fear a new arms race between the two world powers, which are boosting their militaries, redeploying troops and expanding training manoeuvres.