Rubio turns to small Indian city as US faces high oil prices

Announcing the visit, the US State Department had earlier said that it would focus on energy cooperation, commercial investment and economic ties.

The official itinerary also did not include Delhi, which raised some questions, especially from Indian opposition politicians. But analysts say the choice was strategic.

"Delhi is where the trust gap is largest. Officials there are unhappy with a number of decisions and policies from Trump's administration," Michael Kugelman, a senior fellow at the Atlantic Council, told the BBC.

But former Indian ambassador to the US, Meera Shankar, cautions against reading too much into him skipping the capital.

"This was primarily an energy-focused visit," she says. "And after all, Rubio did meet the foreign minister in Mumbai."

The meeting between the two foreign ministers at the Taj Hotel covered trade, investment, energy security and defence cooperation, according to official statements. India's foreign ministry also said both sides welcomed progress in trade negotiations and reaffirmed their commitment to concluding a deal, which has long been in the works.

But once the diplomatic meetings were over, Rubio headed to Jamnagar, where the crown jewel of the Ambani business empire is located. This came to define the trip.

Shankar says the refinery visit "showed how much importance the US is attaching to getting more refined fuel into the market before the November midterms".

Reliance's Jamnagar complex can process about 1.4 million barrels of crude oil a day, roughly 1.5% of global refining capacity, according to the company website.

It is also a major exporter of diesel and other petroleum products, giving it a crucial role in global fuel markets.