PHILADELPHIA — Republican nominee Donald Trump pleaded directly Wednesday with the Russian government to meddle in the U.S. presidential election by finding and releasing tens of thousands of private emails from his Democratic opponent, Hillary Clinton – an extraordinary and perhaps unprecedented maneuver in American politics.

“Russia, if you’re listening, I hope you’re able to find the 30,000 emails that are missing,” Trump said during a news conference at one of his South Florida resorts. He added later, “They probably have them. I’d like to have them released.”

Asked whether Russian espionage into the former secretary of state’s correspondence would concern him, Trump said, “No, it gives me no pause. If they have them, they have them.”

The emails cited by Trump are from Clinton’s time at the State Department, where her use of a private server prompted a federal investigation. The FBI concluded that no prosecution was necessary.

Those are different than emails from the Democratic National Committee that were leaked ahead of the party convention here, possibly with the involvement of Russia. The FBI is investigating whether Russian state actors were responsible for leaking the politically damaging messages last Friday in an episode that forced the resignation of DNC Chairwoman Debbie Wasserman Schultz.

President Barack Obama, who planned to address the convention on Wednesday night, told NBC News in a Tuesday interview that Russia could be working to influence the election.

“What we do know is that the Russians hack our systems, not just government systems but private systems,” Obama said. “What the motives were in terms of the leaks, all that – I can’t say directly. What I do know is that Donald Trump has repeatedly expressed admiration for Vladimir Putin.”

Clinton campaign manager Robby Mook responded to Trump’s Wednesday comments with a tone of disbelief, telling reporters the apparent hacking was “a national security issue.”

“It appears the Russians did steal these emails from the DNC,” Mook said at a lunch sponsored by the Wall Street Journal. “It appears as if they were active in releasing them for the purpose of hurting the campaign.”

Democrats have labored all week to put Trump on the defensive over his business and personal ties to Russia, as well as his professed admiration for its president, Putin, as a model leader. Some have portrayed Trump as Putin’s Manchurian candidate.

The candidate and several of his top advisers have business connections to Russia. Campaign chairman Paul Manafort has made millions of dollars in business deals with pro-Russia oligarchs as well as advised the Putin-aligned president of Ukraine whose 2014 ouster triggered Russia’s intervention there.

Trump seemingly played into Democratic hands on Wednesday by praising Putin’s leadership qualities and vowing that U.S. relations with Russia would improve if he is elected in November.

“I don’t think Putin has any respect whatsoever for Clinton,” Trump said. He added, “He has a total lack of respect for President Obama. Number one, he doesn’t like him. And number two, he doesn’t respect him. I think he’s going to respect your president if I’m elected. And I hope he likes me.”

In a series of afternoon tweets, Trump spokesman Jason Miller said the candidate was merely encouraging other countries to turn over any information relating to Clinton’s emails to U.S. authorities.

“To be clear, Mr. Trump did not call on, or invite, Russia or anyone else to hack Hillary Clinton’s emails today,” Miller wrote.

Still, Trump’s provocation alarmed many Republican leaders and foreign policy experts – not only for his disjointed discussion of Russia, but also for the signal it sent about their standard-bearer’s worldview. Many were also alarmed by Trump’s remark that he would be “looking at” whether Crimea, which Russia seized from Ukraine in 2014, should be recognized as Russian territory.

Rather than approaching Russia with trepidation, Trump embraced Putin as a future ally and said he hoped to develop a chummy and mutually beneficial rapport with one of the globe’s notorious strongmen. In doing so, Trump broke with decades of Republican instincts that were honed during Ronald Reagan’s presidency at the end of the Cold War.

“It is a very big deal,” said Eliot A. Cohen, a former counselor in George W. Bush’s State Department. “Foreign governments sometimes express preferences about who should be elected; that’s already problematic. But to do something in the nature of dirty tricks would be a very, very serious problem.”

Trump’s vice-presidential running mate, Indiana Gov. Mike Pence, issued a statement minutes after Trump’s remarks that hewed closely to established Republican orthodoxy. Instead of baiting the Russians to reveal Clinton’s emails, Pence said that the FBI must “get to the bottom of who is behind the hacking.

“If it is Russia and they are interfering in our elections, I can assure you both parties and the United States government will ensure there are serious consequences,” the statement continued.

A spokesman for House Speaker Paul Ryan, R-Wisconsin, Brendan Buck, said in a statement: “Russia is a global menace led by a devious thug. Putin should stay out of this election.”

It was unclear whether Trump’s declaration would hurt or help him politically. Such comments by a normal candidate in a normal election year would be a seminal and possibly fatal episode. Yet neither Trump nor this year are typical – and as with past controversies, voters may not take Trump’s commentary seriously.

Partisan figures rallied immediately to Trump’s defense, blaming the mainstream media for blowing Trump’s comments out of proportion and trying to shift the focus from Clinton’s judgment.

“What’s irresponsible is that more than 30,000 emails were deleted by a crook who broke the law,” former House speaker Newt Gingrich, R-Georgia, said in an interview. “I don’t care if it’s the Bulgarians, the Chinese or Haitian immigrants studying at Stanford. Let’s see the 30,000 emails.”

Veteran Republican strategist Mike Murphy said many longtime Republicans were appalled by Trump’s gambit.

“This is what happens when you nominate an egomaniacal bozo as your candidate for president of the United States,” Murphy said. “He has jumped the shark into complete embarrassment. … He’ll please his half of the Republican Party every day until the end, but that’s not enough to win a general election.”

On stage here this week at the Democratic National Convention, Clinton’s supporters have tried to cast Trump as a pawn in Russia’s global ambitions.

“The truth is that a Trump victory in November would be a gift to Vladimir Putin, and given what we have learned about Russia’s recent actions, Putin is eager for Trump to win,” former secretary of state Madeleine Albright said. “And that should worry every American.”

Trump has repeatedly tried to do business in Russia, and Russian investors have been important to his real estate empire, particularly in recent years.

In 2008, Trump’s son Donald Jr. told a real estate conference in New York that Russians constitute “a pretty disproportionate cross-section” of Trump’s real estate assets. “We see a lot of money pouring in from Russia,” he added.

According to litigation filed in Florida, Trump’s partners on a Panama project traveled to Moscow in 2006 to sell condos to Russian investors. Trump also sold a mansion in Palm Beach in 2008 for $95 million to Russian oligarch Dmitry Rybolovlev; he had purchased the home at a bankruptcy auction four years earlier for $41.4 million.

Trump has also sought to build a tower in Moscow numerous times since the late 1980s, when he said he had a deal to explore a Trump project in partnership with the Soviet government. His most recent effort came after a Putin ally, Aras Agalarov, known as the Trump of Russia, paid Trump millions to bring the Miss Universe pageant to Moscow in 2013. Agalarov has told The Washington Post that he inked a preliminary deal to bring a Trump project to the Russian capital.

“We will be in Moscow at some point,” Trump promised in a 2007 deposition.

Trump Organization General Counsel Alan Garten also outlined the company’s interest in Russia to The Post in May. “We’re always looking to expand and do projects all over the world. I have no doubt, as a company, I know we’ve looked at deals in Russia. And many of the former Russian republics,” he said.

Trump tried to swat away several questions from reporters on Wednesday about his ties to Russia. “I have nothing to do with Russia,” he told one journalist. “How many times do I have to say that? Are you a smart man? I have nothing to do with Russia.”

Trump has also surrounded himself with aides with ties to Russia, in addition to Manafort. One of his foreign policy advisers, Carter Page, once ran the Moscow office of Merrill Lynch and has advised Russian oil giant Gazprom. Page has said his Russian business associates are excited at the prospect that a Trump presidency would result in the end of Ukrainian-related sanctions on Russia, which has crimped their business.

Another Trump adviser, retired Lt. Gen. Michael Flynn, who was on his vice-presidential shortlist, has advocated a stronger alliance with Moscow to fight Islamic State terrorists. Flynn sat near Putin at a 2015 dinner in Moscow honoring RT, an English-language media service aligned with the Kremlin.

At his news conference Wednesday, Trump imagined his presidency ushering in an era of good relations with Russia.

“I would treat Vladimir Putin firmly, but there’s nothing that I can think of that I’d rather do than have Russia friendly, as opposed to the way they are right now, so that we can go and knock out ISIS together with other people and with other countries,” Trump said. “Wouldn’t it be nice if we actually got along with people?”

DelReal in Milwaukee and The Washington Post’s Rosalind S. Helderman in Washington and Tom Hamburger and Anne Gearan in Philadelphia contributed to this report.