NEW DELHI: When US President Donald Trump and Indian Prime Minister Narendra Modi met last month in France, their camaraderie was on full display as they smiled, laughed and even clasped hands in front of reporters. Now the leaders of the world’s two largest democracies are taking their relationship to the next level: On Sunday, they will appear together at a rally in Houston in front of tens of thousands of people.

For the Indian government, Trump’s presence at the rally is a diplomatic triumph. It marks the first time that any US president and Indian prime minister have addressed such an event together, and it comes at a critical juncture.

In recent months, the United States and India have become embroiled in a trade war, and Trump has complained vociferously about Indian tariffs, even as he has touted his personal rapport with Modi.

India, meanwhile, has faced criticism for its recent moves to strip Kashmir of its autonomy and institute a communications crackdown in the restive north Indian region. The steps sparked tensions with Pakistan and expressions of concern from the State Department and some members of Congress, who have urged India to end its detentions of Kashmir’s political leaders.

Now, with Modi and Trump sharing a stage, the two countries will emphasise their affinities rather than their differences. Modi’s supporters can point to Trump’s presence at the rally as “virtual approval of what [Modi] has done” in Kashmir, said Varghese George, the author of a new book on India-US relations. It’s “a very big deal for Modi and his politics.”

Modi entered office in 2014 and recently won a landslide re-election victory. Like Trump, he has motivated voters with promises to safeguard the nation and restore its greatness. Modi’s brand of politics also views India as fundamentally Hindu, rather than a secular republic as envisaged by its founders.

Modi is very popular at home — his approval ratings far outstrip Trump’s — and he draws large audiences from the Indian diaspora when he travels abroad. About 50,000 people are expected at the rally at Houston’s NRG Stadium, an event aptly titled ‘Howdy, Modi!’ Hundreds of Indian American groups have helped boost attendance.

Milan Vaishnav, who heads the South Asia program at the Carnegie Endowment for International Peace, said he could not remember a time when an American president was the guest at a rally for a foreign leader on US soil. “We have to acknowledge what a spectacle this is,” he said. “Other than maybe the pope, it’s hard to think of this kind of setting happening before.”

Trump’s presence at the event is a “recognition of the importance of the Indian diaspora in the US” and “definitely a recognition of Prime Minister Modi as a global leader,” said Vijay Chauthaiwale, who heads foreign affairs and overseas outreach for India’s ruling Bharatiya Janata Party.

The US-India relationship is anchored by shared strategic interests, added Chauthaiwale. “There will be some differences of opinion on certain issues, maybe on trade or maybe even our move in Kashmir,” he said. “But there is enough maturity to deal with it in a friendly manner.”

For Trump, the rally provides access to a pool of voters — Indian Americans — that he hopes to court in next year’s presidential elections, even if the community tends to lean heavily Democratic.

Officials from both countries have dropped strong hints that they hope to announce progress toward reducing the current trade frictions while Modi is in the United States. If so, it would allow Trump to claim a victory on one of his signature issues.

India’s External Affairs Minister, Subrahmanyam Jaishankar, told reporters Tuesday that he expected to see some of the “sharper edges” in the US-India relationship “addressed in some form in the not-too-distant future”.

Experts said they believed that any imminent trade agreement would probably be modest. On the trade front, the two countries are “trying to undo damage and stop new damage, rather than do exciting, positive things,” said Richard Rossow, a senior adviser at the Centre for Strategic and International Studies in Washington. “You’re at the hospital, not the gym.”

Rossow said that India might make concessions on issues such as its price caps on certain medical devices and possibly ease import restrictions on some agricultural commodities. The United States, meanwhile, could indicate its openness to reinstating preferential treatment for certain Indian imports — a status Trump revoked in May.

After appearing onstage with Trump, Modi will travel to New York for the opening session of the United National General Assembly. He is scheduled to deliver an address there on September 27, his first such appearance since 2014. He also will receive an award from the Bill & Melinda Gates Foundation honouring progress in global health for his ‘Clean India’ campaign that has constructed millions of toilets across the country.

The award from the foundation has become a focus for protesters seeking to draw attention to India’s actions in Kashmir. They recently presented a petition with 100,000 signatures at the foundation’s headquarters in Seattle urging it to retract the honour, which it declined to do.

“India’s a big, complex case, and some of the recent things, I think, people are really questioning, rightly,” Bill Gates said in an interview with The Washington Post’s Ishaan Tharoor. But the award from the foundation is about India’s work on sanitation, Gates said, which has helped combat diseases that kill hundreds of thousands of people a year. “We think the head of government that took these moves on sanitation, that’s worthy of note.”