Potassium iodine pills are being handed out in evacuation centres across Ukrainian capital Kyiv in preparation for a possible Russian nuclear strike.
The chemical compound can help prevent the body absorbing radiation if taken before or immediately after exposure caused by such a blast.
The city council said in a statement, the tablets will be given to residents if there is a need to flee.
Russian President Vladimir Putin has said he will "use all the means at our disposal" to turn his disastrous invasion into a success for the Kremlin.
Moscow's hapless troops are suffering monumental daily losses as determined Ukrainian forces push them out of multiple regions via counterattacking tactics.
As a result, it is feared despot Putin will lose his nerve and resort to a catastrophic nuclear strike.
It comes following reports NATO has warned member nations the war-mongering leader would carry out nuclear testing on Ukraine's border.
The intergovernmental military alliance - which has 30 member states - claimed Russia's K-329 Belgorod sub, which became active in July, could be about to test the Poseidon underwater drone in the Kara Sea.
The weapon is said to be able to cause a 1,600ft nuclear tsunami.
Italian news outlet La Repubblica reported over the weekend that NATO has sent an intelligence report to members regarding the Belgorod's movements.
It is also reported Russia has moved a train possibly linked to a unit of the defence ministry responsible for nuclear munitions.
Kremlin spokesman Dmitry Peskov has responded to claims by saying Russia doesn't want to discuss Western "nuclear rhetoric".
"The Western media, Western politicians and heads of state are engaging in a lot of exercises in nuclear rhetoric right now," Peskov said.
"We do not want to take part in this."
An unnamed Western official downplayed any such activity.
They told the Daily Mail yesterday: "We have not seen any indicators or activities that we would think are out of the norm.
"We have not seen activity which is beyond the usual for the sorts of activities that are conducted by those elements of the Russians' strategic forces."
