New Delhi, June 19 -- Michelle Obama delivered an emotional tribute to former President Barack Obama at the opening of the Obama Presidential Center in Chicago, praising his resilience, leadership, and character.

"Eight years in the crucible and not once did you melt in the heat. Not once did you let it harden you," she said.

She added: "Your stubborn optimism and unflinching courage. Your dazzling brilliance and unpretentious decency. Your ferocious work ethic and absolutely unshakable moral fiber."

Recalling his presidency, she said, "And to do it all as a first," while highlighting major decisions, including "standing up for marriage equality" and "listening to science."

Barack Obama was seen visibly moved during the address, appea...