NEW YORK — India’s new prime minister, once shunned by Washington, appeared before an enthusiastic crowd in a famed New York sports arena Sunday where he appealed for help from Indian-Americans to help develop his country’s economy, vowing that under his leadership, the South Asian nation wouldn’t look back.

A day after addressing a hushed U.N. General Assembly, where headphone-wearing delegates rarely break into a smile, Narendra Modi received a tumultuous welcome from upward of 18,000 people. He struck a chord by announcing plans to simplify the immigration bureaucracy for Indians living abroad, and called on them to “join hands to serve our mother India.”

A dazzling, Bollywood-style show with dancers warmed up the crowd before Modi appeared. About 30 U.S. lawmakers attended – ringing the stage as the Indian leader came into the auditorium under a spotlight like a boxing champion. The event had the feel of a political rally, and the audience periodically broke out into chants of “Modi! Modi!”

On Monday, Modi will meet with President Obama at the White House, a meeting that both sides hope can improve strained relations between the world’s two largest democracies.

Being courted by Washington marks a major change since 2005, when the U.S. denied Modi a visa for his alleged complicity in sectarian violence in his home state of Gujarat.

Several hundred anti-Modi protesters, mostly Americans of Indian descent, both Hindu and Muslim, gathered across the street from Madison Square Garden, chanting behind police barricades, “Modi, Modi, you can’t hide, you committed genocide!”

Inside, Modi spoke in Hindi from a dais at the center of the stage that occasionally rotated so he could face a different section of the audience. He vowed to fight corruption and champion India’s legions of poor whom he said wanted to participate in the nation’s progress.

He also touted India’s promise as a tech giant, joking that it’s no longer known as a nation of “snake charmers.”

“Our country used to play with a snake, now we play with the mouse,” Modi said, drawing laughs and applause.

Modi is no stranger to a big stage. Backed by huge corporate wealth, he was the center of the slickest election campaign India has seen. Madison Square Garden, however, takes it up a notch. It is home to the New York Knicks basketball team and New York Rangers ice hockey team, and was where John Lennon played his last concert. Muhammad Ali fought his first bout against Joe Frazier there.

About 800 people also gathered to watch a live feed of the speech in New York’s Times Square, some holding Indian flags and sporting Modi t-shirts.

At both venues, Indian-Americans likened the enthusiasm over Modi’s meteoric rise to that surrounding Obama, who captured America’s imagination when he won the 2008 presidential election. “We haven’t seen a leader like Obama in our country ’til we’ve seen Modi,” said Raj Thondepu, 33, from Jersey City, New Jersey.