Republican presidential candidate Donald Trump speaks during a campaign rally at Regent University, Saturday, Oct. 22, 2016, in Virginia Beach, Va. AP Photo/Evan Vucci Donald Trump on Tuesday called for an investigation into President Barack Obama after hacked emails from Hillary Clinton campaign chairman John Podesta, published by WikiLeaks, suggested Obama may have known about Clinton's use of a private email server.

In an interview with Reuters, Trump called the revelation "a big thing."

"This means that he has to be investigated," Trump said.

During a rally in Sanford, Florida, on Tuesday afternoon, Trump addressed the latest emails.

"But newly public emails — WikiLeaks — prove otherwise," he said of Obama's knowledge of the private server Clinton used while she was his secretary of state.

The Republican presidential nominee said "now I understand" why Obama supported Clinton in the presidential election.

"Because he didn't want to get caught up in the big lie," he said. "We have to investigate the investigation. We have to investigate."

The latest hacked emails showed top Clinton aide Cheryl Mills' response when Clinton's traveling press secretary, Nick Merrill, forwarded a tweet that quoted Obama as saying he learned about the private server "the same time everybody else" did.

"We need to clean this up," Mills wrote to Podesta. "He has emails from her — they do not say state.gov."

The exchange seemed to imply that Obama knew about Clinton's use of a private email server, which would contradict what he said during an interview with CBS News in March 2015.

When CBS White House correspondent Bill Plante asked Obama when he learned that Clinton used an email system outside the US government for official business while she was secretary of state, Obama responded, "The same time everybody else learned it through news reports."

The White House has addressed this supposed inconsistency. Press secretary Josh Earnest said after the CBS interview aired that Obama "was referring specifically to the arrangement associated with Secretary Clinton's email."

"Yes, the president was aware of her email address," Earnest said. "He traded emails with her. That shouldn't be a surprise that the president of the United States is going to trade emails with the secretary of state. But the president was not aware of the fact that this was a personal email server and that this was the email address that she was using exclusively for all her business. The president was not aware of that until that had been more widely reported."

The FBI investigated Clinton's use of the server, but ultimately declined to recommend the Justice Department move forward with charges against her.

The Clinton campaign has tied WikiLeaks to Russian hackers looking to swing the election in favor of Trump. US intelligence has claimed Russia was behind the hacks of American political organizations in 2016.

Pamela Engel contributed to this report.