He said it was unclear whether the Russian military already had nuclear warheads at the site, or that they are about to bring them in, or whether the facility was being upgraded so that nuclear weapons could be moved in at short notice.
Kaliningrad, formerly the East Prussian outpost of Königsberg, is currently in the public eye as one of the venues for the football World Cup. It is also emerging as a critical square on the east European chessboard in Vladimir Putin’s efforts to push back assertively against Nato expansion.
The Russian military announced in January this year that the necessary infrastructure had been built to accommodate a permanent presence of mobile Iskander-M missiles, capable of carrying conventional and nuclear warheads a range of 500km. The missiles were due to be combat ready early this year.
The US says that because of their range, the Iskanders represent a violation of the 1987 Intermediate-range Nuclear Forces treaty.
Kaliningrad also serves as a base for Russia’s Baltic fleet.
Unlike Nato, the Russian military, particularly its navy, has kept many of its tactical weapons systems nuclear capable, including anti-ship missiles, short range land-attack missiles and even air defences.
As tensions with the west have escalated over Ukraine and Syria, Putin has put more emphasis on Russia’s nuclear arsenal. In March this year, Putin unveiled a range of new nuclear weapon designs which he claimed could overcome any western defences.
Kristensen said it was unclear what kind of warheads the renovated bunker in Kaliningrad is meant to serve, but it is much closer to the naval base than the missile base, which is further inland.