Trump 'called Putin seven times since leaving office'

US Republican presidential candidate Donald Trump has had as many as seven private phone calls with Vladimir Putin since leaving office and secretly sent the Russian president COVID-19 test machines during the pandemic, Bob Woodward reports in his new book, "War."

The revelations were made in the famed Watergate reporter's latest book, which also details President Joe Biden's frustrations with Israeli Prime Minister Benjamin Netanyahu and Saudi Crown Prince Mohammed bin Salman 's assortment of burner phones.

The Associated Press obtained an early copy of the book, which is due out next week.

Steven Cheung, Trump's communications director, denied the accounts in the book.

"None of these made up stories by Bob Woodward are true and are the work of a truly demented and deranged man who suffers from a debilitating case of Trump Derangement Syndrome," Cheung said in a statement.

Woodward reports that Trump asked an aide to leave his office at his Florida resort, Mar-a-Lago, so that the former president could have a private call with Putin in early 2024.

The aide, whom Woodward doesn't name, said there have been multiple calls between Trump and Putin since Trump left office, perhaps as many as seven in that period, according to the book.

Trump's relationship with Putin has been scrutinised since his 2016 campaign for president, when the then-candidate memorably called on Russia to find and make public missing emails deleted by Hillary Clinton, his Democratic opponent.

"Russia, if you're listening, I hope you're able to find the 30,000 emails that are missing," he said.

US intelligence agencies later determined that Russia had meddled in the 2016 election to help Trump, though an investigation by special counsel Robert Mueller found no conspiracy between the Trump team and Russia.

In 2018, Trump publicly questioned that finding following an in-person meeting with Putin in Helsinki.

In recent years, Trump has criticised US support for Ukraine as it fights off Russia's invasion.

He has said Ukraine should have made concessions to Putin before Russia invaded in 2022.

He also previously touted his good relationship with Putin and called the Russian leader "pretty smart" for invading Ukraine.

Woodward also reports that Trump sent Putin COVID-19 test machines for his personal use as the virus began spreading in 2020.

Putin told Trump not to tell anyone because people would be mad at Trump over it, but Trump said he didn't care if anyone knew, according to the book.

Trump ended up agreeing not to tell anyone.

The book doesn't specify when the machines were sent but describes it as being when the virus spread rapidly through Russia.

It was previously reported by The Associated Press and other agencies that Trump's administration in May 2020 sent ventilators and other equipment to several countries, including Russia.

Vice President Kamala Harris, in an interview Tuesday with radio host Howard Stern, accused Trump of giving the machines to a "murderous dictator" at a time when "everyone was scrambling" to get tests.

"This person who wants to be president again, who secretly is helping out an an adversary while the American people are dying by the hundreds every day," said Harris, the Democratic presidential candidate.

The book also details Biden's complicated relationship with Netanyahu as well as private moments when the president has been fed up with him over the Israel-Hamas war.

Biden's "frustrations and distrust" of Netanyahu "erupted" this past spring, Woodward writes.

The president privately unleashed a profanity-laden tirade, calling him a "son of a bitch" and a "bad f***ing guy," according to the book.

Biden said he felt, in Woodward's accounting, that Netanyahu "had been lying to him regularly."

With Netanyahu "continuing to say he was going to kill every last member of Hamas," Woodward wrote.

"Biden had told him that was impossible, threatening both privately and publicly to withhold offensive US weapons shipment."

Biden and Netanyahu have long been acquainted, although their relationship has not been known to be close or overly friendly.

Last week, Biden said he didn't know whether the Israeli leader was holding up a Middle East peace deal in order to influence the outcome of the 2024 US presidential election.