Sessions' latest defense comes as he faces Tommy Tuberville in a tough Republican runoff primary election for Alabama's US Senate seat - a race that pits the man who held the seat for 20 years against a political neophyte.
Sessions went on to attack his opponent, Tuberville. I did my duty and you're damn fortunate I did.
"3 years ago, after Jeff Sessions recused himself, the Fraudulent Mueller Scam began". Sessions had been one of the first high-profile Republicans to endorse Trump's 2016 presidential campaign. Sessions was a former Alabama senator who became the USA attorney general in 2017.
"To not recuse myself from that investigation, of which I was a target as a senior campaign official and a witness, would have been breaking the law", Sessions said in a statement.
On Friday, he responded to Trump's tweet, saying his recusal from the investigation was required by law.
But Sessions resigned as attorney general in November 2018.
Trump tweeted out his support for Sessions' opponent, former Auburn University football head coach Tommy Tuberville but not without taking a shot at his former attorney general by urging his followers not to trust Sessions. "He let our Country down", the President tweeted.
He is now running in the Republican primary to contest his old seat, which the Republicans lost to the Democrat Doug Jones in December 2017 after nominating Roy Moore, a hardline judge who spoke favourably of Vladimir Putin but was accused of, and denied, sexual misconduct involving women as young as 14. "I intend to take my case directly to the people of Alabama".
Trump's message was part of his retweet of a Tuberville message from last Sunday in which Tuberville said Sessions had thrown Trump "to the wolves with the Mueller appointment". When faced with supporting POTUS or running scared, Jeff Sessions chose the easy way out and recused himself.
In a tweet, Trump appeared to tie Sessions' firing to special counsel Robert Mueller's Russian Federation investigation, linking to a post from Sessions' Senate race rival that accused him of "running scared" when he recused himself from control of the Russian Federation investigation in 2017.
A May survey suggested 55 percent of voters favoring Tuberville, with 32 percent supporting Sessions according to Newsweek. Sessions was the first US senator to endorse Trump, donning a Make America Great Again hat at an Alabama rally.