Donald Trump secretly sent American Covid tests to Vladimir Putin for his personal use, a new book has claimed.

The former president allegedly supplied the Kremlin with tests, which were in short supply, to be used by Putin at the height of the Covid pandemic.

Bob Woodward, the veteran American reporter who broke the Watergate scandal, said a former Trump aide had told him about the shipment.

In his new book, War, Mr Woodward said that Putin had cautioned Trump not to reveal that he had supplied the tests because he might face a public backlash.

Mr Woodward wrote that the Russian leader told Trump: “I don’t want you to tell anybody because people will get mad at you, not me.”

Trump has faced criticism for his alleged fondness for Putin. The book claims that the two men held a phone call in early 2024, as Joe Biden prepared to send more weapons to Ukraine.

Trump has said that he would end the war in Ukraine by the time he is inaugurated if he wins this year’s presidential election. His approach to the war is a major point of difference with Kamala Harris, who said on Monday she would not meet Putin without Volodymyr Zelensky, the Ukrainian president.

Mr Woodward’s book alleges that Trump has secretly maintained a close relationship with Putin since he left the White House in January 2021.

The book claims that they have spoken as many as seven times, leading its author to the conclusion Trump is a worse president than Richard Nixon, who resigned over Watergate.

“Trump was the most reckless and impulsive president in American history and is demonstrating the very same character as a presidential candidate in 2024,” Mr Woodward wrote.

The book also reveals details about Mr Biden’s approach to world leaders. Behind closed doors, he is accused of describing Benjamin Netanyahu, the Israeli president as a “son of a b----” and a “bad f---ing guy”.