U.S. President Barack Obama has praised Hillary Clinton as an exceptionally qualified candidate for the presidency, saying the "choice isn’t even close" in her race for the White House against Republican nominee Donald Trump.
"There has never been a man or woman, not me, not Bill [Clinton] -- nobody more qualified than Hillary Clinton to serve as president of the United States," Obama told the Democratic National Convention in Philadelphia as the crowd cheered.
In a speech brimming with optimism, Obama laid out a bright vision of the country's future that Clinton will deliver if she wins the November 8 election.
He called Clinton, who formally accepted the Democratic nomination a day earlier, "fit and...ready to be the next commander in chief" of the United States, saying her long record of public service -- including as secretary of state and a U.S. senator -- made her uniquely qualified for the White House.
"Nothing truly prepares you for the demands of the Oval Office," Obama said. "You can read about it. You can study it. But until you've sat at that desk, you don't know what it's like to manage a global crisis or send young people to war. But Hillary's been in the room; she's been part of those decisions."
Clinton electrified the crowd when she walked on stage as Obama concluded his speech, embracing the president on a night that included speeches by Vice President Joe Biden, former New York Mayor Michael Bloomberg, and her running mate, Senator Tim Kaine of Virginia.
"This year, in this election, I'm asking you to join me -- to reject cynicism, reject fear, to summon what's best in us, to elect Hillary Clinton as the next president of the United States," Obama said as he wrapped up his remarks.
The president and other speakers sharply criticized Trump, a wealthy businessman and former reality-TV star who has never held public office, as a fear-monger who makes empty promises and has a dark vision of the country.
WATCH: Obama Says America 'Already Great' Without Trump
Biden called Trump "a man who seeks to sow division in America for his own gain, and disorder around the world" and "a man who confuses bluster with strength."
Trump scorned the optimistic tone of the convention's third night, writing on Twitter that the country does not feel "great to the millions of wonderful people living in poverty, violence, and despair."
Taking 'Russia's Side'
Several speakers during the evening accused Trump as being overly friendly toward Russia, whose relations with Washington have plunged to Cold War-level lows since Russia's forcible annexation of Ukraine’s Crimean Peninsula in 2014 and its backing of separatists fighting Kyiv's forces in eastern Ukraine.
The criticism follows last week's massive leak of e-mail correspondence among Democratic officials that the party has suggested was orchestrated by the Russian government. The leak triggered outrage from supporters of Clinton's rival for the nomination, Senator Bernie Sanders, after the e-mails showed that ostensibly neutral party officials favored Clinton.
Trump drew scorn from Democrats for saying earlier on July 27 that he hopes Russia would be able to find "the 30,000 e-mails that are missing," a reference to correspondence that Clinton said she deleted from the private server because she considered them personal.
The FBI has investigated whether Clinton violated laws in her handling of classified materials, calling her "extremely careless" but saying last month that she would not face charges.
Former U.S. Defense Secretary and Central Intelligence Agency (CIA) chief Leon Panetta told the convention that Trump was "once again" taking "Russia’s side" by suggesting that Moscow should track down Clinton's e-mails.
"Donald Trump, who wants to be president of the United States, is asking one of our adversaries to engage in hacking or intelligence efforts against the United States of America to affect an election," Panetta said.
"As someone who was responsible for protection our nation from cyberattacks, it is inconceivable to me that any presidential candidate would be that irresponsible," he added.
Trump has said he would seek to improve ties with Moscow if elected. He also suggested on July 27 that if elected, he would consider recognizing Crimea as part of Russia and lifting sactions that the United States imposed on Russia in reponse to its seizure of the peninsula from Ukraine.
"We'll be looking at that. Yeah, we'll be looking," he said when asked whether he would recognize Crimea as Russian territory and lift the sanctions if elected president.
Biden, meanwhile, portrayed Trump as sympathetic to "dictators," citing positive statements the Republican nominee has made about Russian President Vladimir Putin.
Adding that Trump would make the United States "less safe," Biden said, "We cannot elect a man who belittles our closest allies, while embracing dictators like Vladimir Putin."
Clinton made history at this week's convention, becoming the first woman to be chosen to lead a major U.S. political party's bid for the White House.
She is set to formally accept the nomination at the convention on July 28.