India, June 5 -- A 50% tariff on steel and aluminium imports into the United States went into effect on Wednesday, doubling the previous rate as President Donald Trump cited national security concerns for the dramatic escalation in trade protections.

The new tariff rates, increased from an earlier 25% rate, were announced by Trump in a statement on Tuesday. The president claimed legal authority to impose the tariffs through Section 232 of the Trade Expansion Act of 1962, which allows the president to address national security risks arising from imports.

"In my judgement, the increased tariffs will more effectively counter foreign countries that continue to offload low-priced, excess steel and aluminium in the United States market and th...