Sessions sent a letter to President Donald Trump announcing his resignation.

News reports indicated that Sessions resigned after more than a year of a tempestuous relationship with Donald Trump, following his withdrawal from the Robert Mueller-led investigation into possible collusion between the Trump election campaign and Russia.

Meanwhile, Trump announced in a tweet that Sessions’ chief of staff Matthew Whitaker will take over as acting attorney general, and a permanent candidate will be nominated later.

In a statement, Whitaker said he is committed to “leading a fair department with the highest ethical standards, that upholds the rule of law and seeks justice for all Americans.”

Considering that Whitaker was vocal in his stance against the Robert Mueller investigation into Trump’s ties with Russia, it is likely he will be in charge of this matter when he assumes the position of Attorney General.

At a press conference, Trump said he was happy with his cabinet ministers for the most part but it was just hours after that Sessions resigned.

Sessions’ exit is a result of a highly toxic relationship that worsened weeks into the Attorney General’s tenure when he stepped away from investigations into Trump’s possible ties to Russia during his presidential campaign.