ISLAMABAD, Jan. 14 -- Pakistan has limited options to respond after US President Donald Trump announced a 25 per cent tariff on any country doing business with Iran, analysts say. The move, issued via social media and effective immediately, marks a sharp escalation in Washington's economic pressure campaign against Tehran.

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The tariff targets third countries, not Iran itself, forcing them to weigh economic engagement with Tehran against access to the US market. Pakistan's bilateral trade with Iran, estimated at around $3 billion annually, has grown steadily and is often conducted through barter or local currency arrangements, reflecting both sanctions constraints and dollar shortages....