Donald Trump has threatened to "substantially" raise tariffs against India over its purchase of oil from Russia, BBC reported.

"They [India] don't care how many people in Ukraine are being killed by the Russian War Machine," the US president wrote on his online platform, Truth Social, on Monday.

India is currently among the largest buyers of Russian oil. It has become an important export market for Moscow after several European countries cut trade when Russia launched its full-scale invasion of Ukraine in 2022.

Trump did not specify what the new tariff would be, but it comes just days after he unveiled a hefty 25% levy on India, according to BBC.