U.S. President Donald Trump again threatened on Monday to raise tariffs on goods from India over its Russian oil purchases, while New Delhi called his attack "unjustified" and vowed to protect its economic interests, deepening the trade rift between the two countries.

In a social media post, Trump wrote, "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."

"Because of this, I will be substantially raising the Tariff paid by India to the USA," he added.