Officials want to create a "military Schengen zone" similar to the EU's civilian passport-free travel area by simplifying customs checks and bureaucracy that currently cause hold-ups for NATO forces and vehicles trying to cross borders.

Top NATO commanders say the changes are essential if Europe is to have a serious deterrent to potential Russian aggression, warning that cumbersome checks are hampering their ability to move resources quickly.

Working with EU member states, over the next year the European Commission, the bloc's executive arm, will carry out an assessment of existing bureaucratic hurdles and transport infrastructure to see where and how improvements can be made.

"We must be able to quickly deploy troops either within the EU or rapidly launch military operations abroad and to do so we need infrastructure that is fit for purpose," EU transport commissioner Violeta Bulc told reporters.

The EU plans do not mention Russia specifically but tensions with Moscow have been high since the Ukraine crisis and Kremlin's annexation of Crimea in 2014 -- and the current diplomatic spat over the nerve agent attack on a former Russian spy in Britain has done nothing to calm matters.

"There is a practical dimension to these proposals, but the end purpose is obvious as soon as tensions rise with Russia," a European diplomat said.

Another warned that "we can no longer say that conflict in Europe is impossible".

US General Ben Hodges, commander of US ground forces in Europe at the time, in October last year said that to create an effective deterrent to Moscow, NATO needed to move forces "as quick or quicker than Russian Federation forces".

"What we have called for is something similar to a military Schengen zone. To have that same sort of freedom of movement a truck full of Polish apples has," Hodges said.

- Erratic delays -

The Baltic states of Estonia, Latvia and Lithuania, annexed and ruled by the Soviet Union for decades and deeply aware of the threat from their giant neighbour, have already created a military mini-Schengen among themselves, Elisabeth Braw of the Atlantic Council think tank said.

NATO has deployed around 4,000 troops along with tanks and artillery in Poland and the Baltic countries both as a sign of determination and to be ready if a crisis erupts.

Elsewhere, the pattern is erratic. Some countries have streamlined procedures for moving vehicles and dangerous goods such as ammunition, others not.

"If you want to take a military truck with general cargo into Italy you only have to give 48 hours notification, whereas in other countries you have to give up to 14 working days," Braw told AFP.

In some cases, military convoys have to be registered months in advance in exacting detail, down to number plates and drivers' names, severely restricting commanders' ability to adapt their plans.

- Roads, bridges, tunnels -

While troops can be moved by air, moving an armoured brigade's worth of tanks needs roads and railways, and boosting European infrastructure is a key part of the plan.

The EU is already in the process of upgrading key transport corridors around the continent and plans to adapt the projects to take military needs into account.

EU countries -- working with NATO -- will draw up a list of military requirements by the middle of this year which will then be compared against existing transport infrastructure and plans to upgrade it.

Then a list will be drawn up of "dual use" projects -- situations where improvements can be made that will satisfy both military and civilian needs.

"Concrete examples could include upgrading a bridge that is currently unable to support military vehicles or heavy trucks transporting civilian goods," Bulc said.

After the end of the Cold War, the need for military movement around Europe declined as there was no longer thought to be a danger of invasion, but the events in Crimea and Ukraine in 2014 once again brought the threat from the east back into sharp focus.