Quote: Estonian officials have said that Russia appears to be moving powerful, nuclear capable missiles into Kaliningrad, a Russian outpost province sandwiched between Poland and Lithuania along the Baltic coast.

The Iskander-M missiles, which have a range of over 500km, are reportedly being transported by ship from the St Petersburg area. It had previously been reported that the Russians might seek to place the Iskander-M missiles in Kaliningrad but not until 2018-19.

If confirmed, the move would be seen by western governments as another sign that Russia is seeking to establish facts on the ground, from eastern Europe to the Middle East, before a new US president takes office in January.

Estonian officials said they were monitoring the ship and its contents. The ship, called the Ambal, was due to dock on Friday; reports of the cargo came from Estonian government sources.

An Estonian defence expert said: “This weapon is highly sophisticated and there is no comparable weapon in western armoury. It can carry nuclear weapons, change direction mid-flight and fly distances of up to 500km. As such it is capable of threatening Poland, including the US missile defence installations there. You would not change the date of the delivery of a system such as this on a whim. The intention is to make a strong strategic point.”