A scheduled trip by a U.S. trade delegation to India later this month has been called off, according to reports. Several rounds of talks on a bilateral trade deal between the U.S.—the world's largest economy—and India, the world's most populous nation and itself a major economic power, have so far failed to yield an agreement.

A planned visit by U.S. trade negotiators to New Delhi from August 25-29 has been called off, a source said, delaying talks on a proposed trade agreement and dashing hopes of relief from additional U.

U.S. President Donald Trump last Wednesday announced 25% tariffs on Indian imports from August 7 and threatened more penalties over New Delhi's purchases of Russian oil. Below is a timeline of how India,