President Donald Trump's landmark Asia trip, which concluded on Tuesday, revealed his growing reliance on India as a strategic partner in the region.

But if Washington wants Prime Minister Narendra Modi's administration to be at the core of its Asia policy, it must help New Delhi on issues crucial to its own future, experts said. Those include supporting Indian membership in the Asia-Pacific Economic Cooperation forum and assisting with New Delhi's other geopolitical concerns.

India and the Indo-Pacific

Trump's frequent use of the term "Indo-Pacific" as a replacement for "Asia-Pacific" — the more widely used label in diplomatic and business circles — revealed the level of importance Washington places on New Delhi.

During a speech in Vietnam, the U.S. leader highlighted his desire for a "truly free and open Indo-Pacific," repeating the term after Secretary of Defense James Mattis and Secretary of State Rex Tillerson used it in earlier remarks.

The label's usage underscores "India's geographic connection to the Asia-Pacific as a cornerstone of the Trump administration's strategic thinking," Alyssa Ayres, senior South Asia fellow at the Council on Foreign Relations, said in a note this week.

The "free and open" part of Trump's statement also adds an ideological aspect to regional security and was widely seen as a reference to Beijing's behavior in the South China Sea. New Delhi, which isn't one of America's treaty allies but nonetheless enjoys a robust bilateral relationship based on shared democratic values, has a significant role to play in that.

"Like it or not, or hide it or not, the term Indo-Pacific now seems to be a means of including India in the military calculations of U.S. strategy in the Pacific," Manoj Joshi, distinguished fellow at think tank Observer Research Foundation, said in a recent note.

New Delhi is also a major player in a newly-resurrected informal defense alliance aimed at offsetting Chinese maritime aggression. Consisting of the U.S., Australia, Japan and India, the partnership was first launched in 2007 in what many saw as a maneuver to contain rising Chinese power. The coalition, known as the "Quad," eventually fell apart — but under Tokyo's initiative, resumed at the recent ASEAN Summit in Manila.

The Quad's revival in itself isn't a major development, but combined with the White House's newly asserted focus on a free and open Indo-Pacific, Washington is "pointedly wooing New Delhi into what could well be a military alliance," Joshi said.

The world's second-largest economy has expressed reservations about the Quad, with a Chinese foreign ministry spokesman saying Monday that regional cooperation should neither be "politicized" nor "exclusionary."

Supporting India

If Washington is going to rely on India as a strategic partner, it should help Modi's administration strengthen its position in Asia, said Ayres, a former deputy assistant secretary for South Asia at the U.S. State Department.

The U.S. should expend diplomatic capital to make Indian membership into the influential Asia-Pacific Economic Cooperation a reality, a move that could offset Chinese influence and "help the larger Indo-Pacific region balance its economic center of gravity better," she explained.

India, Asia's third-largest economy, remains excluded from the economic bloc despite a membership request dating back more than 20 years.

APEC membership would also help New Delhi gain a greater role in institutions of global governance and send a strong message about increasing free and open trade, Ayres continued.

Trump could also do more to help Modi's administration with other geopolitical concerns.

"For all its talk of the Indo-Pacific,

Modi's administration is concerned about terrorist attacks on Indian soil from Pakistan-based militants as well as overall stability in Iran, a major oil supplier to New Delhi.