(Adds background on controversy, Pence quote)
WASHINGTON, Oct 17 (Reuters) - President Donald Trump said on Tuesday that Tom Marino, his pick as the U.S. drug czar, has withdrawn after it became public that the congressman advocated for legislation undermining the government's ability to crack down on pharmaceutical companies that play a role in the nation's opioid crisis.
Trump had pegged Marino, a Pennsylvania Republican, to lead the Office of National Drug Control Policy, a post that required Senate confirmation.
Trump wrote on Twitter: "Rep. Tom Marino has informed me that he is withdrawing his name from consideration as drug czar. Tom is a fine man and a great Congressman!"
The Trump administration has taken criticism for its response to the opioid epidemic.
Trump said on Aug. 10 he would declare the opioid epidemic a national emergency, but has not yet done so. Such a declaration would help unlock resources including additional funding and expanded access to various forms of treatment, and would give the government more flexibility in waiving rules and restrictions to expedite action.
Asked about the emergency declaration at a news conference on Monday, Trump said, "We are going to be doing that next week. ... It's a very important step. And to get to that step, a lot of work has to be done, and it's time-consuming work."
The U.S. Centers for Disease Control and Prevention said that 33,000 deaths were linked to opioids in 2015, the last year with publicly available data.
The Washington Post and CBS News published an investigation on Sunday that showed that Marino had worked to weaken federal efforts to slow the flow of opioid drugs.
U.S. Vice President Mike Pence said the administration continues to think "very highly" of Marino.
A spokeswoman for Tom Marino's office said the congressman had no immediate comment. (Reporting by Makini Brice; Editing by Will Dunham)