PARIS - France has started the withdrawal of its military from Chad with the departure of two warplanes that were based in the capital N'Djamena, the French army said, two weeks after Chad said it was ending its defense cooperation pact with Paris.

In a surprise move, the government of Chad - an ally of the West in the fight against Islamist militants in the region - ended the defense cooperation pact on Nov 28.

Terms and conditions of the withdrawal and whether any French troops will remain in the central African country altogether have yet to be agreed, but on Tuesday the first Mirage warplanes returned to their base in eastern France.

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"It marks the beginning of the return of French equipment stationed in N'Djamena," Army spokesperson Colonel Guillaume Vernet said after two Mirage fighter jets left Chad.

France has already pulled its soldiers out of Mali, Burkina Faso and Niger following military coups in those West African countries and spreading anti-French sentiment.

The departure from Chad will end decades of French military presence in the Sahel region and ends direct French military operations against Islamist militants there.

France still has about 1,000 troops in Chad. Vernet said a calendar to drawdown its operations would still take several weeks for the two countries to finalize.

Chad's Army spokesman, Chanane Issakha Acheikh, confirmed the departure of the French warplanes and said that the public would be kept informed on the withdrawal "until the definitive departure of the (French) forces."

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There were no indications Paris received advance notice of Chad's decision to end its defense cooperation although a French envoy to President Emmanuel Macron delivered a report last month containing proposals on how France could reduce its military presence in Chad, Gabon and Côte d'Ivoire.