DUBAI - India has made an advance payment of $800 million for Russia's S-400 anti-aircraft missile systems, the head of Russian conglomerate Rostec Sergey Chemezov told reporters on Monday.

Chemezov said negotiations were underway and a contract with India will be completed in 2025.

(Reporting by Stanley Carvalho; Writing by Alexander Marrow; Editing by Maria Kiselyova) ((alexander.marrow@thomsonreuters.com; +7 495 775 1242))