Russia said Wednesday its forces had carried out simulated nuclear missile strikes in the western enclave of Kaliningrad on the border with the European Union.
The announcement came on the 70th day of Moscow's military action in the pro-Western country, with thousands killed and more than 13 million displaced.
After sending troops to Ukraine in late February, Russian President Vladimir Putin has made thinly veiled threats about Russia's willingness to deploy tactical nuclear weapons.
During Wednesday's war games, Russia practiced "electronic launches" of nuclear-capable Iskander mobile ballistic missile systems near Russia's borders with EU-members Lithuania and Poland, the defense ministry said in a statement.
The Russian forces practiced single and multiple strikes at targets imitating missile systems, airfields, defended infrastructure, military equipment and command posts, according to the statement.
The units involved also practiced "actions in conditions of radiation and chemical contamination."
More than 100 servicemen took part in the drills.
Russia placed nuclear forces on high alert shortly after the start of the invasion of Ukraine.
Putin has warned of a "lightning fast" retaliation if the West directly intervenes in the Ukraine conflict.
In recent days, Russian state-owned media has attempted to make the use of nuclear weapons more palatable to the public.
"For two weeks now, we have been hearing from our television screens that nuclear silos should be opened," Russian newspaper editor and Nobel Peace Prize laureate Dmitry Muratov said Tuesday.