Washington | A bipartisan group of US Senators unveiled a bill that seeks to impose 100 per cent tariffs on five countries, including India and China, for purchasing oil from Russia.

The bill, brokered by late Republican Senator Lindsey Graham, exempts 15 European nations that buy gas from Russia from the tariffs, arguing that the purchases amount to a fraction of their total requirement and the countries in question were taking steps to reduce dependence on Moscow.

Apart from India and China, other countries that will be hit by the tariffs are Slovakia, Hungary and Azerbaijan.

"It's been referred to as a tariffs bill, but actually it imposes full blocking sanctions on wide swaths of the Russian economy, including its energy industry, financial industry, defence industrial base, oligarchs, business people, and Vladimir Putin himself," Richard Blumenthal, a Democratic Senator from Connecticut, told reporters here Tuesday evening.

"It imposes tariffs that are targeted: narrowly limited to the five major purchasers – up to 100 per cent – with waiver authority that is narrowly tailored and constricted. And those five major purchasers, right now, of oil are China, India, Slovakia, Hungary, Azerbaijan," Blumenthal said.

If the bill passes, it would be the first time that the Congress has explicitly authorised the use of tariffs as a geopolitical weapon with the goal of punishing countries financing another nation's war effort.

An earlier version of the bill sought to impose 500 per cent tariffs on purchasers of oil and gas from Russia.

Blumenthal said "our European allies are not targeted here". "It is very important to understand that we have so narrowly crafted and tailored and targeted this bill to aim at the major purchaser of Russian oil and gas." At the press conference on Capitol Hill, Republican and Democratic senators stood shoulder-to-shoulder to present the bill as a tribute to Graham, the South Carolina senator, who passed away in the wee hours of Sunday.

Senator Katie Britt, a Republican from Alabama, said Graham had worked "tirelessly, relentlessly" to bring the measure together and believed it would become the most consequential legislation of his career.

Senator Roger Wicker, a Republican from Mississippi, described the bill as Graham's greatest achievement in the cause of preserving peace in Europe.

Senator Jeanne Shaheen, a Democrat from New Hampshire and the ranking member of the Foreign Relations Committee, urged Congress to seize the "narrow window to pass the legislation".

Last month, the US proposed to impose 12.5 per cent tariffs on 54 countries, including India, for allegedly failing to prohibit the import of goods produced with forced labour.