Shoigu arrived in the Belarusian capital city earlier in the day to partake in a meeting of the Collective Security Treaty Organization at the level of defense ministers.
"During a meeting, [the sides] signed documents defining the procedure for maintaining Russian non-strategic nuclear weapons in a special storage facility on the territory of Belarus," the ministry wrote on Telegram.
The deployment of non-strategic nuclear weapons is a response to the aggressive policy of unfriendly countries, the ministry added.
Shoigu said during the ministerial meeting that Russia and Belarus were forced to make appropriate decisions on retaliatory measures in the military-nuclear sphere due an "extremely sharp escalation of threats" on both countries' western borders.
"I would like to note that all the activities are organized strictly in accordance with existing international obligations and do not violate the Treaty on the Non-Proliferation of Nuclear Weapons," the Russian defense chief added.
He also stressed that the Western countries were doing "everything possible" to escalate the Ukraine conflict.
Russian President Vladimir Putin said on March 25 that Moscow and Minsk had agreed to station Russia's tactical nuclear weapons in Belarus, which does not breach Russia's commitments on the non-proliferation of nuclear weapons. On April 2, Russian Ambassador to Belarus Boris Gryzlov said that nuclear weapons in Belarus would be stationed closer to the western borders of the Union State.