U.S. President Donald Trump's threat to impose secondary tariffs of 25% to 50% on buyers of Russian crude oil is just crazy and bold enough to perhaps achieve his stated aim of a ceasefire in Ukraine.

Donald Trump has threatened to impose huge secondary sanctions on all buyers of Russian oil if Vladimir Putin continues to delay a ceasefire agreement in Ukraine, a move that would significantly impact major importers India and China.

The proposed tariffs, which range from 25 to 50 percent, would not directly target Russia but would penalize foreign countries that continue trading with it.