New Delhi has put on hold its plans to procure new U.S. weapons and aircraft, according to three Indian officials familiar with the matter, in India's first concrete sign of discontent after tariffs imposed on its exports by President Donald Trump dragged ties to their lowest level in decades.

India, which now faces among the highest tariff rates imposed by the US, called the levy "unjustified and unreasonable".

US President Donald Trump has imposed 50 per cent tariff on Indian imports, citing New Delhi's imports of Russian crude. Announced on Wednesday, the 25 per cent levy takes the earlier announced tariffs of the same amount on Indian imports to US to a the highest imposed by Washington on any trading parner. It is set to take full effect by August 27.