President Trump in the Oval Office on Tuesday. (Jabin Botsford/The Washington Post)

The FBI on Wednesday pushed back on an unfounded claim by President Trump that Hillary Clinton’s emails were hacked by China, saying it had found no evidence that the private servers she used while secretary of state had been compromised.

Trump asserted early Wednesday, without citing evidence, that China had hacked Clinton’s emails, and he said the Justice Department and the FBI risked losing their credibility if they did not look into the matter further.

Writing on Twitter, Trump alleged that many of the emails that were purportedly hacked contained classified information and called it “a very big story.”

“Hillary Clinton’s Emails, many of which are Classified Information, got hacked by China. Next move better be by the FBI & DOJ or, after all of their other missteps . . . their credibility will be forever gone!” Trump wrote in a tweet posted shortly after midnight.

Trump provided no details about the alleged hacking, but his tweets came shortly after the online publication of a story by the Daily Caller asserting that a Chinese-owned company operating in the Washington area hacked Clinton’s private server while she was secretary of state and obtained nearly all her emails. The publication cited “two sources briefed on the matter.”

Fox News, which is frequently watched by the president, aired a segment on the report Tuesday night, with a guest calling it a bombshell if true.

Asked about the president’s assertions, the FBI provided a statement Wednesday afternoon that simply said: “The FBI has not found any evidence the servers were compromised.”

An FBI spokesman declined to comment on Trump’s call for the bureau to make a “next move.” A spokesman for the Justice Department also declined to comment.

Democrats, as well, seized on Trump’s remarks.

“Mr. President, you have at your disposal the resources of the nation’s law enforcement agencies and intelligence community. Use them,” Rep. Adam B. Schiff (Calif.), the top Democrat on the House Intelligence Committee, said in a tweet.

In an earlier tweet Tuesday night, Trump wrote: “Report just out: ‘China hacked Hillary Clinton’s private Email Server.’ Are they sure it wasn’t Russia (just kidding!)? What are the odds that the FBI and DOJ are right on top of this? Actually, a very big story. Much classified information!”

Trump has long focused on Clinton’s use of private servers as secretary of state and contends that the FBI did not sufficiently investigate the matter.

During the 2016 campaign, in which Trump faced off against Clinton, then-FBI Director James B. Comey announced that the agency had found no basis to bring criminal charges against Clinton, the Democratic nominee.

In a July 2016 statement, Comey said the FBI “did not find direct evidence that Secretary Clinton’s personal e-mail domain, in its various configurations since 2009, was successfully hacked.” But, he added: “Given the nature of the system and of the actors potentially involved, we assess that we would be unlikely to see such direct evidence.”

A lengthy Justice Department inspector general report released in June criticized the latter part of Comey’s statement, saying that while forensics agents could not say with 100 percent confidence that Clinton’s servers had not been compromised, they were “fairly confident” that there wasn’t an intrusion.

Trump’s calls to investigate Clinton and other real and perceived political adversaries have grown louder as the special counsel’s investigation into Russian interference in the 2016 election continues.

Special counsel Robert S. Mueller III is probing whether the Trump campaign coordinated with Russia during the election and whether Trump has sought to obstruct the investigation.

Speaking in Beijing, Chinese Foreign Ministry spokeswoman Hua Chunying said accusations about Chinese hacking were nothing new.

“This isn’t the first time that we’ve heard this kind of accusation,” Hua said at a daily news briefing.

“China is a staunch defender of cybersecurity,” she added, without specifically mentioning Trump or Clinton. “We firmly oppose and crack down on any form of Internet attacks and the stealing of secrets. China advocates that the international community jointly respond to cybersecurity threats through dialogue and cooperation, on the basis of mutual respect, equality and mutual benefit.”

Yang Liu in Beijing contributed to this report.