"India has long had a field day putting Tariffs on American products. No longer acceptable!" Trump tweeted.

There was no immediate comment from India's foreign and trade ministries.

But an Indian government source with close knowledge of the matter said Trump and Indian Prime Minister Narendra Modi had a "very good meeting" in Osaka in June and they were continuing to engage on the issue.

Trump and Modi met on the sidelines of the G20 summit in Japan.

Christopher Wilson, the US assistant trade representative for South and Central Asia, was expected to meet Indian government officials in New Delhi on Friday, two senior Indian trade ministry officials said.

Indian government sources said last month that Indian tariffs were not that high compared to other developing countries and some US tariffs much higher.

The United States and India are grappling with issues that include access to Indian markets for US firms, New Delhi's demand for foreign firms to store Indian data in the country and Indian exports of steel and aluminium to the US market.

The trade row has prompted both countries to raise tariffs and created unease over the depth of their security alliance.

In May, Trump scrapped India's trade privileges under the Generalized System of Preferences (GSP), under which New Delhi could make duty-free exports worth up to $5.6 billion.

In response, New Delhi slapped higher tariffs on 28 US products.