Russia will start supplying its S-400 surface-to-air missile systems to India in the fourth quarter (October-Dec) this year, the Interfax news agency reported on Thursday based on information from Russian state-owned arms exporter Rosoboronexport.

India had at the peak of the Ladakh border military standoff with China requested Russia to expedite the delivery of the missile system when defence minister Rajnath Singh visited Moscow.

A team of Indian military personnel is currently in Russia to receive training for operating the missile system. India plans to equip five regiments with the state-of-the-art S-400 missiles which will be delivered in phases.

India had signed a $5 billion deal for S-400 missiles in 2018 to strengthen the country’s air defence system.

The US has been opposed to the deal under its Countering America’s Adversaries Through Sanctions Act or CAATSA. However, India’s consistent stand has been that the process had started much before CAATSA was imposed by the US. New Delhi has also expressed the view that any sanctions under this clause are not part of a UN law.

Russian Foreign Minister Sergei Lavrov said during his recent visit to New Delhi that the United States has been trying to discourage countries from buying Russian weapons. However, he had also said such U.S. objections did not feature during his talks with Indian foreign minister S.Jaishankar, which had focused on deepening military ties.

Russia and India are discussing "additional" production of Russian military equipment in India, Lavrov said.