(NBC News) - Hillary Clinton, in her first public remarks since her stunning defeat in the race for the White House, urged Americans on Wednesday not to give up on the values they embraced in her.

"I know how disappointed you feel, because I feel it, too," Clinton told a room full of supporters. "This is painful and it will be for a long time, but I want you to remember this: Our campaign was never about one person or even one election. It was about the country we love and building an America that's hopeful, inclusive, and big-hearted."

"I still believe in America, and I always will," she said.

The Democratic nominee called Donald Trump sometime in the wee hours of Wednesday morning to concede after the real estate mogul pulled off a shocking upset, capping off an election where all conventions were seemingly thrown to the wayside.

In her speech Wednesday, she asked Americans to accept the results.

"I hope that he will be a successful president for all Americans," she said of Trump. "We must accept this result and look to the future. We owe him an open mind and a chance to lead."

Clinton had not made a statement after conceding initially, instead quietly exiting the Manhattan convention center where her lavish Election Night party was taking place. Singers Katy Perry, Lady Gaga, and Cher were in attendance, ready to perform if Clinton clinched a win.

Those in the room on Wednesday when she was speaking included longtime Clinton friends and former diplomats, as well as members of her senior staff, including top aide Huma Abedin. Her husband, former President Bill Clinton, was also there.

The room gave her a standing ovation. Some had tears in their eyes.

Clinton was introduced Wednesday by her running mate, Tim Kaine, who said he was proud of her because "she has been and is a great history-maker."

"We know she would have made history as a president," he added.

In a jab to their opponent, who repeatedly called the election "rigged" during his campaign, Kaine also said, "Nobody had to wonder about Hillary Clinton, whether she would accept an outcome of an election in our beautiful democracy."

By nearly every indication, Clinton looked poised for a win. Even after an 11th-hour bombshell from FBI Director James Comey on the email controversy that has dogged her campaign, polls in the days leading up to the election showed the former Secretary of State ahead by 4 points.

On Election Day, her emotional supporters had filled social media with photos of themselves bringing their daughters to their polls to vote for the first female presidential candidate.

But as the night wore on and she faltered in one key battleground state after another, global financial markets plummeted into chaos. The Mexican peso, a bellwether of the 2016 election, hit a record low on fears that Trump would implement policies that would hurt free trade between Mexico and the U.S.

Clinton thanked voters Wednesday and told them that they, too, will experience setbacks, but they shouldn't be discouraged.

"This loss hurts, but never stop believing that fighting for what right is worth it," she said. "To all the women and especially the young women who put their faith in in this campaign and especially in me, I want you to know that nothing has made me prouder than to be your champion."

"And to all the little girls that are watching this, never doubt that you are valuable and powerful and deserving of every chance and opportunity in the world to pursue and achieve your own dreams."

Democrats woke up Wednesday shell-shocked, still soaking in the reality of a Republican-controlled Congress and White House.

President Barack Obama called Trump early Wednesday to congratulate him and invited him to a meeting at the White House on Thursday, and he was expected to make a statement in the afternoon.

"It was a very warm conversation," Trump campaign manager Kellyanne Conway told TODAY. "They resolved to work together, which is exactly what this country needs … to help unify and heal the country."

Both the president and first lady Michelle Obama had valiantly campaigned for Clinton. At a Philadelphia rally on the eve of the election, Michelle Obama described Clinton as someone "who sees us not as Democrats and Republicans, but as neighbors and friends who all love this country, who sees us not just as black or white, immigrant or native-born, but as brothers and sisters who are all infinitely worthy, all an important part of this great American story."

Obama called Clinton after speaking to Trump Wednesday morning.