File Photo: U.S. President Donald Trump (C) waits for the arrival of Irish Prime Minister Leo Varadkar at the White House in Washington D.C., the United States, on March 15, 2018. (Xinhua/Ting Shen)

WASHINGTON, March 18 (Xinhua) -- The White House on Sunday denied that U.S. President Donald Trump is considering firing Special Counsel Robert Mueller amid strong backlash against Trump's threats to the investigations into Russian meddling in the 2016 presidential election.

"In response to media speculation and related questions being posed to the administration, the White House yet again confirms that the president is not considering or discussing the firing of the Special Counsel, Robert Mueller," White House lawyer Ty Cobb said in a statement.

File Photo: Former FBI Director Robert Mueller (front), the special counsel probing Russian interference in the 2016 U.S. election, leaves the Capitol building after meeting with the Senate Judiciary Committee on Capitol Hill in Washington D.C., the United States, on June 21, 2017. (Xinhua/Ting Shen)

The statement came after a back-and-forth regarding Mueller's position and his ongoing probe into the Trump campaign's alleged collusion with Russia.

Trump has launched repeated attacks on Mueller in a series of tweets over the weekend, saying his probe "should never have even been started."

"It was based on fraudulent activities and a Fake Dossier paid for by Crooked Hillary and the DNC (Democratic National Committee), and improperly used in FISA COURT (U.S. federal court established and authorized under the Foreign Intelligence Surveillance Act) for surveillance of my campaign. WITCH HUNT!" he tweeted.

"Why does the Mueller team have 13 hardened Democrats, some big Crooked Hillary supporters, and Zero Republicans?" Trump tweeted Sunday.

"And yet, there is NO COLLUSION!" he added.

Trump tweets on the Russia probe.

The renewed assault on Mueller has raised concerns among many lawmakers, and even some in Trump's Republican party have advised Trump to drop the threats.

U.S. Republican Senator from South Carolina Lindsey Graham told the press that "The only reason Mr. Mueller could ever be dismissed is for cause. I see no cause when it comes to Mr. Mueller. He needs to be able to do his job, independent of any political influence."

"I pledge to the American people, as a Republican, to make sure that Mr. Mueller can continue to do his job without any interference," Graham, who has been at odds with Trump on a number of issues, said.

If Trump tries to fire Mueller, "that would be the beginning of the end of his presidency," Graham said.

Activists carry placards with political points of view gather before marching through downtown Los Angeles on June 3, 2017, in the March For Truth, part of a peaceful nationwide demonstration aimed at restoring faith in American Democracy and the U.S. electoral system. (Xinhua/AFP)

"We need to be very careful about taking these very important entities and smearing everybody in them with a broad stroke," Republican Senator from Florida Marco Rubio said Sunday.

Lawmakers have also expressed dismay over the Justice Department's firing of former deputy director of the Federal Bureau of Investigation Andrew McCabe late Friday, saying he should have been allowed to stay on until Sunday, when he was eligible to retire with a full pension.