The Maldives has signed a "military assistance" deal with China after ordering Indian troops deployed in the small but strategically-placed archipelago to leave, officials said Tuesday.

Some 89 Indian military personnel in the country will be gone by May 10 after having been previously ordered out by pro-China President Mohamed Muizzu, who came to power last year on an anti-Indian platform.

The Maldivian defence ministry said they signed an "agreement on China's provision of military assistance" with Beijing late Monday, saying the agreement was "gratis", or without payment or charge, but giving no further details.

The defence ministry said the deal was to foster "stronger bilateral ties", in a post on social media platform X.

India is suspicious of China's growing presence in the Indian Ocean and its influence in the Maldives, as well as in neighbouring Sri Lanka.

Both South Asian island nations are strategically placed halfway along key east-west international shipping routes.

Relations between Male and New Delhi have chilled since Muizzu won elections in September.

Addressing a public rally north of the capital on Monday, Muizzu vowed there would be no Indian troops on Maldivian soil after May 10, when they are expected to complete a withdrawal.

The Indians had been deployed to operate three reconnaissance aircraft New Delhi had gifted Male to patrol its vast maritime boundary.

India is expected to replace the military personnel with civilian staff to operate the aircraft, and the Maldives defence ministry announced last month that Indian civilian crew had begun arriving in the atoll nation.

Last month, Male allowed a controversial Chinese research ship to enter its waters in a sign of the nation's diplomatic reorientation towards Beijing and away from its traditional benefactor India.

China's Xiang Yang Hong 3 arrived in Male after being refused permission to dock by Sri Lanka following objections from India, which has labelled it a spy ship.

China also gave 12 electric ambulances to the Maldives on Sunday, the health ministry said.