Russia has started the delivery of S-400 surface-to-air missile systems to India, according to a senior Russian official.
Russia's Director of the Federal Service for Military-Technical Cooperation (FSMTC) Dmitry Shugaev told Sputnik news that the deliveries are going as planned.
"The supplies of the S-400 air defence system to India have started and are proceeding on schedule," he said.
In October 2018, India had signed a USD 5 billion deal with Russia to buy five units of the S-400 air defence missile systems, despite a warning from the Trump administration that going ahead with the contract may invite US sanctions.
India made the first tranche of payment of around USD 800 million to Russia for the missile systems in 2019.
The S-400 is known as Russia's most advanced long-range surface-to-air missile defence system.
Following US sanctions on Turkey over the procurement of S-400 missile systems, there have been apprehensions that Washington may impose similar punitive measures on India.