U.S. President Donald Trump leaves the White House in Washington D.C., the United States, on Oct. 25, 2019. (Photo by Ting Shen/Xinhua)

Former Vice President and the presumptive Democratic presidential nominee Joe Biden Saturday criticized Trump's failure to punish Russia as "a betrayal of the most sacred duty."

WASHINGTON, June 28  -- U.S. President Donald Trump said on Sunday that he was never briefed on intelligence that Russians offered bounties to Taliban-linked militants for killing U.S. troops.

"Nobody briefed or told me, @VP Pence, or Chief of Staff @MarkMeadows about the so-called attacks on our troops in Afghanistan by Russians, as reported through an 'anonymous source' by the Fake News @nytimes," Trump tweeted Sunday morning.

"Everybody is denying it & there have not been many attack on us," he added.

Casualty records, however, showed that the year of 2019 was the deadliest year for U.S. service members in Afghanistan since 2014, with 22 American troops killed.

Trump's tweets echoed the White House Saturday statement on this matter, in which Press Secretary Kayleigh McEnany said several senior officials had confirmed that neither Trump nor Vice President Mike Pence was briefed on the intelligence.

McEnany also noted that the statement "does not speak to the merit of the alleged intelligence but to the inaccuracy of the New York Times story erroneously suggesting that President Trump was briefed on this matter."