WASHINGTON — The Trump administration imposed sanctions on a Ukrainian lawmaker Thursday for waging “a covert influence campaign” to undermine the presidential election after he disseminated information intended to hurt former Vice President Joseph R. Biden Jr.
The Treasury Department accused Andriy Derkach, a member of the Ukrainian Parliament, of being “an active Russian agent for over a decade” and accused him of releasing “edited audiotapes” and “unsubstantiated allegations against U.S. and international political figures.”
While the announcement of the sanctions does not name Mr. Biden, the Democratic presidential nominee, it appears to describe recordings Mr. Derkach released of Mr. Biden talking to Petro O. Poroshenko, the former president of Ukraine, that Mr. Derkach claimed revealed corruption.
“Andrii Derkach and other Russian agents employ manipulation and deceit to attempt to influence elections in the United States and elsewhere around the world,” Steven Mnuchin, the Treasury secretary, said in a statement accompanying the sanctions. “The United States will continue to use all the tools at its disposal to counter these Russian disinformation campaigns and uphold the integrity of our election system.”
The Treasury Department also announced sanctions against three employees of the Internet Research Agency, a Russia-based troll farm that spread disinformation on social media as part of Russia’s election interference campaign in 2016.
While Mr. Mnuchin has been steadfast in his loyalty to President Trump, the sanctions in some ways put the men at odds on an issue of great significance to the president.
Mr. Trump has pushed unsubstantiated claims that Mr. Biden used his position as vice president to pressure the Ukrainian government to protect his son, who served on the board of a gas company owned by an oligarch who was widely seen as corrupt. A campaign waged by Mr. Trump and his personal lawyer, Rudolph W. Giuliani, to pressure the Ukrainian government to investigate the matter led to the president’s impeachment last year by the House of Representatives.
But Mr. Trump has continued calling attention to the matter, including promoting some of the material released by Mr. Derkach as recently as last month. Mr. Giuliani met with Mr. Derkach in December in Kyiv during a trip intended to collect damaging information about the Bidens, first reported by The New York Times.
Mr. Giuliani did not respond to a request for comment. The White House did not immediately respond to a request for comment.
The Office of the Director of National Intelligence warned last month that Russia was “using a range of measures” to primarily harm Mr. Biden, specifically noting Mr. Derkach’s release of audio recordings.
Representative Adam B. Schiff, Democrat of California and chairman of the House Intelligence Committee, praised the Treasury sanctions in a statement as “appropriate and welcome,” and chided Mr. Trump for promoting “the same false claims and smears.”
As a result of Thursday’s actions, Mr. Derkach and the other individuals will have any assets or properties they hold in the United States frozen.
The Justice Department also filed charges on Thursday against one of the Russians who was penalized by the Treasury Department. Artem Mikhaylovich Lifshits was charged with wire fraud conspiracy for using the stolen identities of real U.S. persons in the troll-farm scheme to meddle in American politics.
Alan Rappeport contributed reporting from Washington, and Andrew E. Kramer from Moscow.