Belarus, which hosts Russian nuclear weapons, said on Monday its armed forces had begun training on how to deploy them in the field.
The move underscores rising tensions between Moscow and the West over the Ukraine conflict and NATO's expanding footprint in Eastern Europe.
Focus on Mobility, Stealth, and Coordination
'During the training, in cooperation with the Russian side, it is planned to practise the delivery of nuclear munitions and their preparation for use,' the Belarusian Defence Ministry said in a statement.
It said the exercise would test the military's readiness to deploy nuclear weapons in different areas of the country.
'The emphasis will be on practicing stealth, movement over significant distances, and calculations for the use of forces and equipment,' the ministry said.
Belarus shares borders with Russia, Ukraine and three NATO states.
Rising Nuclear Tensions in the Region
President Alexander Lukashenko agreed in 2023 - a year after Russia's invasion of Ukraine - to host Russian tactical nuclear missiles. Russian President Vladimir Putin has made clear that Moscow retains control of their use.
Throughout the conflict, Putin has issued reminders of Russia's nuclear might that the West has seen as warnings not to intervene too deeply in support of Ukraine.
Last week, Putin said that Russia would deploy its new Sarmat nuclear missile by the end of the year, and that Moscow would continue to modernise its nuclear forces.
Belarus said the current exercise was not aimed against any other state and did not pose security threats in the region.
(With inputs from Reuters)