Air cargo exports from India to the United States have plunged following the US decision to double tariffs on Indian goods, reports New York's Sourcing Journal.

Cargo volumes fell 12 per cent in the week the 50 per cent duties took effect, followed by another 14 per cent drop in early September, according to WorldACD data.

The US had previously imposed 25 per cent tariffs on Indian imports from August 7, which were raised to 50 per cent on August 27 due to India's continued purchases of Russian oil.

A brief surge in shipments occurred in the week prior to the increase, with volumes up 28 per cent week-on-week and 35 per cent year-on-year, as exporters rushed to beat the deadline.

Spot air freight rates from India to the US fell below US$4 per kilogram for the first time in months, reaching $3.99 in the first week of September - 22 per cent lower than last year.

India's overall exports to the US dropped 14.4 per cent in August to $6.86 billion, down from $8.01 billion in July, according to trade ministry figures.

Textile and apparel exports were hit particularly hard, contracting 2.7 per cent to US$2.9 billion in August, compared to a 5.4 per cent rise in July.

Apparel faces additional most-favoured nation tariffs, with knitted goods taxed at 13.9 per cent and woven items at 10.3 per cent, compounding the impact of the 50 per cent rate.

The suspension of the duty-free de minimis provision on August 29 further slowed India's outbound air cargo, prompting a shift in freight to other global markets.

Air cargo volumes from India to Europe rose 8 per cent year-on-year in early September, while Sri Lanka's exports to the US jumped 13 per cent.

Global tonnages fell 3 per cent in the same week, largely due to reduced volumes from North America, attributed to the Labour Day holiday.

Asia Pacific-to-US tonnages rose 5 per cent over the past 10 weeks, despite declines from China, Hong Kong and South Korea. Taiwan, Vietnam and Thailand saw average annual gains of 40 per cent.

China and Hong Kong are also redirecting freight to Europe, with August volumes to the US flat month-on-month but down five per cent year-on-year. Europe-bound shipments rose 12 per cent annually.