A number of members of the US Congress raised with Foreign Secretary Vijay Gokhale the issue of India signing a deal with Russia for a nuclear submarine last week, official sources said on Saturday.
Gokhale clarified that India finalised the deal for leasing of a nuclear-powered attack submarine from Russia and it was not an acquisition or a purchase, they said.
However, the issue was not raised by the US administration during Gokhale's three-day visit to Washington earlier this week.
Some members of the Congress raised the issue as they have some mis-perception about it, the sources said, adding Gokhale also explained to them that the submarine will only have conventional weapons.
In January, the US announced sanctions against Russia under which Washington can punish countries and entities engaged in transaction with defence or intelligence establishment of Russia.
The sanctions were imposed for Moscow's alleged meddling in the US presidential election in 2016.
On March 7, India sealed a USD 3 billion deal with Russia for leasing of a nuclear-powered attack submarine for the Indian Navy for a period of 10 years.
In October last year, India inked an agreement with Russia to procure a batch of the missile systems at a cost of Rs 40,000 crore. India went ahead with the deal notwithstanding the US's warnings against it.
Under the deal for submarine, Russia will have to deliver an Akula class submarine, to be known as Chakra III, to the Indian Navy by 2025.
It will be the third Russian submarine to be leased to the Indian Navy.
The first Russian nuclear-powered submarine -- christened INS Chakra -- was taken in 1988 under a three-year lease. A second INS Chakra was taken on lease in 2012 for a period of 10 years.