The announcement comes a day after his Russian counterpart Vladimir Putin ordered nuclear drills in Russia, raising fears the powerful weapons could be used in Ukraine.

Non-strategic nuclear weapons, also known as tactical nuclear weapons, are designed for battlefield use and can be delivered via missiles.

They are less devastating than the strategic nuclear weapons used to obliterate entire cities but are still massively destructive and have never been used in combat.

"In accordance with an order from the President of Belarus, a sudden inspection of non-strategic nuclear weapons carriers is being carried out," the Belarusian defence ministry said.

The inspection will test the "planning, preparation and use of strikes with tactical nuclear warheads" and involve a squadron of Su-25 aircraft, it added.

Lukashenko said the inspection was for "purely defensive" purposes and that the army was practising how to launch "missile strikes to repel a possible attack on Belarus".

"We have never in our lifetime been so close to the brink of nuclear war. I'm a peaceful man, I don't want war," he said at a speech commemorating upcoming Victory Day.

Belarus does not have any nuclear weapons itself, but last year agreed to host Russian tactical warheads on its territory amid rising tensions over Ukraine.

Putin has upped his nuclear rhetoric since the Ukraine conflict began, warning in his address to the nation in February there was a "real" risk of nuclear war.

Last year Russia ditched its ratification of the Comprehensive Nuclear Test Ban Treaty and pulled out of a key arms reduction agreement with the United States.