"He gave two to friends of his in case he was killed," Giuliani, who shared information from the drive with the New York Post this week, claimed.

For anyone thinking such words may be a bit extreme, Giuliani insisted it was a real concern, because of "very dangerous" people trying to protect the Bidens.

"Don't laugh," he told the interviewer. "The presidency is at stake and we have some very dangerous people involved. I've been in law enforcement long enough to know you don't laugh at that. The reality is, he kept four copies and gave two to friends in case he was killed."

Joe Biden has denied the legitimacy of Giuliani's claims and called the Post report on his son a "smear campaign."

Despite questions over the authenticity of damaging content from a hard drive allegedly belonging to Joe Biden's son, Hunter, Donald Trump has said the data is a "proven fact," with Steve Bannon promising there is more to come.

Former White House Chief Strategist Steve Bannon, who was brought in to help with the release of the Hunter Biden data, has also promised that much more is to come, including emails he claims are from Hunter Biden's attorney requesting the hard drive back.

"Hunter Biden's lawyer has come to us both with phone calls and with emails saying, 'Hey, I've got to get the hard drive back,'" Bannon told Sky News on Sunday.

"They admit it's their hard drive," he added, promising that if the emails need to be released, "we will release them."

In a separate interview with the Revolver over the weekend, Bannon promised that "We already have set in motion the various apparatuses that will release everything," and said "The Bidens are about to be hit with multiple stories from multiple media sources based off evidence beyond the hard drive."

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The US State Department has warned the Turkish government of "potential serious consequences" to the two nations' security relationship should reports of Ankara testing the Russian S-400 air defense systems prove true.

"If confirmed, we would condemn in the strongest terms the S-400 test missile launch as incompatible with Turkey's responsibilities as a NATO ally and strategic partner of the United States," State Department spokeswoman Morgan Ortagus said on Friday.

Ortagus insisted that the air defense system "should not be operationalized," adding, "We have also been clear on the potential serious consequences for our security relationship if Turkey activates the system."

Washington's reaction comes after a Reuters report showed "a narrow column of smoke headed high into the blue sky" near the city of Sinop in northern Turkey. According to the outlet's defense analyst Turan Oguz, the smoke pattern suggested it was a missile launch of the Russian-made S-400.

The Turkish defense ministry said it would neither confirm nor deny any missile tests. Ankara has previously said it intended to make the S-400s it had purchased from Moscow fully operation by the end of 2020.

Turkey has already received a lot of backlash from the US over its procurement of the air defense system. Following the delivery of the first four missile batteries from Russia in August 2019, Washington suspended Turkey from the F-35 fighter-jet program, and has threatened further sanctions.

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