The Los Angeles mayor told his Senate confirmation hearing that he will "actively raise" human rights if confirmed as President Joe Biden's choice as ambassador.

"I'll raise them with humility -- it's a two way street on these -- but I intend to engage directly with civil society," Garcetti said.

"There are groups that are actively fighting for human rights of people on the ground in India that will get direct engagement from me."

US policymakers across party lines broadly support warmer relations with India, seeing common cause with a fellow democracy faced with a rising China, but several lawmakers have voiced alarm over rights under Prime Minister Narendra Modi.

The Hindu nationalist leader has pushed forward a controversial citizenship law that critics say marginalizes the Muslim minority.

Senator Bob Menendez, who leads the Senate Foreign Relations Committee, pointed to concerns with India over "reports of democratic backsliding and discrimination against religious minorities."

"New Delhi will need to address our concerns if it seeks to deepen our partnership even further," Menendez said.

Both Menendez and his Republican counterpart, Jim Risch, also voiced concern about India's recent announcement that Russia has begun delivery of the S-400 missile defense system.

Under a 2017 law, the United States is required to impose sanctions over significant weapons deals with Russia and it has already done so after Turkey bought the S-400.

Unlike Turkey, a NATO ally whose ties with the West have drifted, India has historically bought weapons from Russia but has seen its relationship grow rapidly with Washington over the past two decades.

Garcetti said Secretary of State Antony Blinken would decide whether to waive sanctions but that as ambassador he would be "very clear about what the threats are to our systems" if they operate alongside Russian hardware.

A State Department spokesperson said Blinken had not made a decision on sanctions but that the United States was urging all countries to "avoid significant new transactions for Russian weapons systems."

Garcetti, who is barred from seeking a third term as mayor next year, has been seen as a rising star in Democratic Party politics and flirted with a presidential run.

The 50-year-old told the committee that he developed a lifelong interest in India after a visit as a university student and began studying Hindi and Urdu.