Washington: The Biden administration is looking whether to apply or waive sanctions on India for its purchase of the S-400 Triumf missile defence system from Russia, under Countering America's Adversaries Through Sanctions Act (CAATSA), said US diplomat Donald Lu said on Wednesday (local time).

Lu's remarks came as India drew criticism from US lawmakers, both Republicans and Democrats, at a hearing on the "US relationship with India" for being among 35 nations that abstained Wednesday from a UN vote to rebuke Russia's invasion.

A concern that stood out repeatedly in the hearing was the India-US defence security cooperation and whether India would be sanctioned for its purchase of the S-400 Triumf missile defence system from Russia, under CAATSA.

Lu said that the Biden administration is yet to decide on applying sanctions on India under CAATSA.

"What I can say is that India is a really important security partner of ours now and that we value moving forward that partnership," he said.

As the US strengthens its ties with India as a pivotal regional counterweight to China, the Biden administration has delayed enforcement of a law ordering sanctions on India for trading with Russia.

India has been the largest importer of Russian arms since 2016. Lu informed the Sun panel that India had recently cancelled orders of Russian MiG-29 fighter aircraft, helicopters and anti-tank weapons, and he projected that the new sanctions would motivate other countries to do likewise.

He told lawmakers it is unlikely Russia will be able to make new sales or provide maintenance to customers for existing systems.

"My view is that it's going to be very hard for anyone to buy major weapon systems from Moscow in the coming months and years, given sweeping financial sanctions that the administration, with the support of Congress has levelled...I would guess that India is one of those countries worried about that," Lu added.

Notably, voting results displayed on screens at the UN General Assembly showed that 141 nations voted in favour of the move condemning Russia's invasion of Ukraine and five nations were against it, with 35 countries, including India, abstaining.