Belarus had declared itself a nuclear-free zone after the break of the former Soviet Union in 1991.
ADVERTISEMENTBelarusian President Alexander Lukashenko says his country would be ready to host "nuclear weapons" if threatened by the West.
Lukashenko also said that Minsk could deploy "super nuclear weapons" if their "rivals and opponents" took "foolish, unreasonable steps".
Tensions between Russia -- an ally of Belarus -- and NATO have reached unprecedented levels over troop movements near Ukraine.
Lukashenko visited an Osipovsky nuclear weapons storage site on Thursday as part of joint Russian-Belarusian military drills.
"If necessary ... we will deploy not only nuclear weapons but also super nuclear weapons -- promising weapons -- in order to defend our territory," Lukashenko said, according to national media.
"If there were no threats from unfriendly countries to Belarus, there would be no need for nuclear weapons here for a hundred years," he added.
After the break-up of the former Soviet Union (USSR) in 1991, Belarus gave up the nuclear weapons deployed on its territory under US pressure.
The weapons were returned to Russia and the Belarusian Constitution then declared that the country would remain a "nuclear-free zone".
But the country is set to vote in a referendum later this month on a constitutional amendment proposed by President Lukashenko which could allow the deployment of Russian nuclear weapons in Belarus.
Lukashenko is also expected in Russia on Friday for talks with his counterpart and ally Vladimir Putin.