PM Modi used electricity as an analogy for ties. "Here (in US) you use a system that is 120 volts, and in India, we use 220 volts. 120 volts and 220 volts will start working together. We need to make the systems work together," he said, flanked by US Secretary of State John Kerry and Vice President Joe Biden.
He was speaking after his talks with President Obama, which went beyond the expected 90 minutes.
PM Modi used more word play to praise Mr Biden and Mr Kerry: "In political life it is so easy to take a simpler path. It is easy to draw a line in butter but to etch a line in stone you need courage. Both leaders have this temperament."
Speaking before the Indian PM, Mr Kerry listed many parallels between India and the US.
"We have two countries that begin the Constitution with 'We the People'. Two countries that have created Hollywood and Bollywood. Two countries that have Bangalore and Silicon Valley. This moment is going to be the moment when the world's largest democracy and the world's oldest democracy capitalize on ties," he said.