You shouldn't always take what Trump says seriously. China and India don't have a dead economy because they have one of the fastest-growing economies in the world.  And both countries are major trading partners of the US. Trump's attacks are to put pressure on Russia to accept a ceasefire in Ukraine.

But the US has the economic power to reduce the growth of the Chinese and Indian economy since the US is their biggest foreign export market. It is predicted that the 25% tariff on Indian exports to the US will affect the economy of India.