Rubio called India an "ally" but noted that Delhi's Russian oil imports were hampering its relationship with Washington.

U.S. President Donald Trump's demand on India to halt Russian oil imports could threaten billions in Russian revenues, prompt Moscow to retaliate by stopping a major U.S.-led oil pipeline and potentially lead to a new global supply crisis.

India has bought a nearly constant flow of Russian oil for the past two years. Prices fluctuated, but each year’s sales have been worth approximately $275 billion. Iraq and Saudi Arabia, traditionally India’s biggest suppliers, have been pushed to the side.