By William Horobin

PARIS--The chief of France's armed forces, Pierre de Villiers, resigned Wednesday after a spat with French President Emmanuel Macron over defense spending.

Mr. Macron's government said earlier this month his government would cut the defense budget by 850 million euros ($981 million) this year as it attempts to repair the country's finances.

In comments to a closed-door hearing at the National Assembly that leaked in the French press, Mr. de Villiers expressed concern about the cuts. Mr. Macron told army chiefs in a speech Thursday that it was undignified to have the debate in public and warned them not to cross him.

Mr. de Villiers said in his resignation statement that it was his duty to express his concerns about the financing of the French army.

"In the current circumstances, I consider I am no longer able to ensure the durability of the model of the army that I believe in to guarantee the protection of France and French people, today and in the future," Mr. de Villiers said.

Write to William Horobin at william.horobin@wsj.com