The statement from ground army chief of staff General Pierre Schill comes after President Emmanuel Macron said he would not rule out dispatching ground troops to help Ukraine fight Russia.

The French army "is ready", Schill wrote in an op-ed piece in French daily Le Monde.

"However the international situation may evolve, French people can be certain that their soldiers stand ready to respond," he said.

Schill said a display of French military capabilities would help to "deter any attack on France".

"To protect itself from any attack and to defend its interests, the French army is preparing for even the toughest engagements," he said.

He quoted the Latin adage "si vis pacem, para bellum" -- "if you want peace, prepare for war".

Schill said that France could engage a division of 20,000 troops in a coalition within 30 days and could itself command an army of around 60,000 soldiers by joining other allied nations.

The French army says it counts 121,000 soldiers and can call up 24,000 reservists.

Schill did not specifically refer to the invasion of Ukraine by Russia and the risk of the conflict spreading. But he said "the sources of crisis are multiplying and carry with them risks of spiralling or extending".

His comments are the latest stark assessment of the situation by a top European military commander.

Britain's chief of the general staff, General Patrick Sanders, said in January that British citizens should be prepared to fight in a potential land war.

Sweden's army chief Micael Byden also alarmed many of his compatriots when he said "Swedes have to mentally prepare for war".

Macron's stance toward Russian President Vladimir Putin has been hardening, with the French leader recently describing Putin as a threat not just to Ukraine but to the security of all Europeans.

France has also blamed Russia for a flurry of cyberattacks and disinformation campaigns.

Macron, who has stated repeatedly that "Russia cannot win this war", shocked European allies in February by refusing to rule out the sending of Western ground troops.

He has also described the Ukraine war as "existential" for Europe.

However, French deputies and experts have worried publicly about a lack of equipment and ammunition which they say would cut short any direct confrontation with a strong enemy after only a few months.