New Delhi, Aug 7 (PTI) NSA Ajit Doval has said during his meetings in Moscow that dates for Russian President Vladimir Putin's visit to India are being worked out, according to sources.

No specific date or time has been indicated by the NSA in his engagements, they said on Thursday.

"NSA Doval, during his visit to Moscow, has said that the dates for President Putin's visit to India are being worked out," said a source.

The time of end-August being reported in some media is incorrect, the sources said.

Doval held talks with Russian Security Council Secretary Sergey Shoigu and other senior officials that focused on bilateral energy and defence cooperation as well as Putin's visit to India.

Prime Minister Narendra Modi had travelled to Russia twice last year for an annual summit with Putin and to attend the BRICS Summit in Kazan.

The Russian president is visiting India for the annual summit this year.

Doval's visit to Russia comes amid some strain in ties between India and the US over New Delhi's continuing procurement of Russian crude oil, notwithstanding Western sanctions on Moscow.

US President Donald Trump on Wednesday issued an executive order slapping an additional 25 per cent tariff on Indian goods as a penalty for New Delhi's continued purchase of Russian oil.

The additional duties raised the overall tariff on India to 50 per cent.

Defending its purchase of Russian crude oil, India has been maintaining that its energy procurement is driven by national interest and market dynamics.

People familiar with Doval's visit to Moscow said bilateral energy and defence ties as well as Western sanctions on Russian crude oil figured in his talks with Russian officials.

Russia has emerged as India's top energy supplier since the West slapped sanctions on its crude oil after the invasion of Ukraine.

The NSA was also expected to press Moscow to ensure early delivery of remaining two regiments of S-400 air defence systems to India.

The S-400 systems played a crucial role during Operation Sindoor.

India signed a USD 5.43 billion deal with Russia in 2018 for five squadrons of the S-400 Triumf missile system, a state-of-the-art air defence platform capable of engaging multiple aerial threats at long ranges.

Three squadrons have already been delivered. PTI MPB ZMN

Tariff penalty on trade: additional duties imposed over India's Russian oil purchases, affecting energy and defence procurement ties. Trade penalties have been applied as a tariff response to India's purchase of Russian crude, creating regulatory friction between sanctions enforcement and India's assertion of procurement by national interest. Diplomatic talks in Moscow addressed the sanctions' impact on energy supplies and sought assurances on timely delivery of remaining S-400 air-defence regiments under an existing multi-squadron defence procurement contract.