US President Donald Trump said on Monday he will substantially raise tariffs on India over its purchases of Russian oil.

“India is not only buying massive amounts of Russian Oil, they are then, for much of the Oil purchased, selling it on the Open Market for big profits. They don’t care how many people in Ukraine are being killed by the Russian War Machine,” Trump said in a post on Truth Social.

“Because of this, I will be substantially raising the Tariff paid by India to the USA.”

He did not elaborate on what the tariff would be.

Trump last week said he would impose a 25 percent tariff on goods imported from India and added that the world’s fifth-largest economy would also face an unspecified penalty but gave no details.

Over the weekend, two Indian government sources told Reuters that India will keep purchasing oil from Russia despite US Trump’s threats. The sources did not wish to be identified due to the sensitivity of the matter.

On Sunday, a top aide to Trump accused India of effectively financing Russia’s war in Ukraine by purchasing oil from Moscow.

“What he (Trump) said very clearly is that it is not acceptable for India to continue financing this war by purchasing the oil from Russia,” said Stephen Miller, deputy chief of staff at the White House and one of Trump’s most influential aides.

Miller’s criticism was some of the strongest yet by the Trump administration about one of the United States’ major partners in the Indo-Pacific.

“People will be shocked to learn that India is basically tied with China in purchasing Russian oil. That’s an astonishing fact,” Miller said on Fox News’ “Sunday Morning Futures.”