France has warned Germany that it could trigger a nuclear conflict with Russia if it does not define how it would use its newly acquired long-range missiles.

Several countries including Germany the UK, Poland and others have taken steps to bolster their defences in a bid to deter Moscow from any attacks on Europe.

As part of this preparation, Berlin is reportedly acquiring and developing ground-range missiles with ranges varying from 500km to more than 2,000km.

But French and German officials are set to hold talks on how these will be used amid fears that their use could trigger a “nuclear response” from Russia, according to the Financial Times. The confusion centres around the definition of deep precision strikes (DPS).

An attack on a Russian target with a conventional weapon could be spark a far greater response from Russia if the signalling is not interpreted right.

“If the Russians don’t get the signal right you could get to the nuclear threshold without realising,” said one French official.

This would have a knock-on effect on France due to president Emmanuel Macron’s “forward deterrence” policy, which means Moscow could hold Paris accountable for strikes by its partners.

“If you invite someone into your house, you are responsible if they set it ablaze,” said one official with knowledge of the discussions.

Six people familiar with the talks told the FT that French officials are hoping to come to an agreement on how both countries could better align their defence programmes in light of this risk.

There is a focus on Germany due to its large defence budget of €780bn in the five year period until 2030.

“There are habits we developed over time. The Germans do not have it,” said one source. “It would be much better to have a clear and pretty public doctrine so that the Russians never get a signal wrong or misunderstand.”

A senior German official said that Berlin agreed that European capitals needed “a joint doctrine and a joint understanding about the escalation ladder” and “could not agree more” with the assessments.

But a British official felt that the fears may be overestimated at the present moment considering that “Germany’s strategic culture is evolving very quickly”. He added that “we absolutely believe we should embrace that, not cling to the past stereotypes”.

It follows reports emerging earlier this year that Germany is in talks to fund Britain’s Trident programme in an attempt to bolster Europe’s nuclear deterrent in any war against Putin.