WASHINGTON – Congressional negotiators on Wednesday approved an initiative to track and combat foreign propaganda amid growing concerns that Russian efforts to spread “fake news” and disinformation threaten U.S. national security.

The measure, part of the National Defense Authorization Act approved by a conference committee, calls on the State Department to lead governmentwide efforts to identify propaganda and counter its effects. The authorization is for $160 million over two years.

If approved by the full House and Senate, the measure could reach President Barack Obama in December. It would be the most significant initiative against foreign governments’ disinformation campaigns since the 1990s.

“This propaganda and disinformation threat is real, it’s growing, and right now the U.S. government is asleep at the wheel,” Sen. Rob Portman, R-Ohio, said in a statement. “The U.S. and our allies face many challenges, but we must better counter and combat the extensive propaganda and disinformation operations directed against us.”

The initiative grows out of a bill authored in March by Portman and Sen. Chris Murphy, D-Conn., called the “Countering Foreign Propaganda and Disinformation Act.” It initially sprang from a desire to help independent journalists and nongovernmental organizations in European nations such as Ukraine, Moldova and Serbia, which face a heavy tide of Russian propaganda.

But the context shifted in recent months as independent experts warned that Russia was carrying out an intensive propaganda campaign during the U.S. election season. The effort helped push misleading reports on the Internet and into voters’ social-media feeds, experts concluded.

U.S. Sen. Angus King and several of his colleagues on the Senate Intelligence Committee also sent a letter to President Barck Obama urging him to declassify information relating to the Russian government and the U.S. election.

Russian officials have consistently denied meddling in the U.S. election, but concerns over the issue have run high amid reports this year of Russian hackers’ infiltrating the computers of elections officials in several states and stealing sensitive emails from the Democratic National Committee and John Podesta, Hillary Clinton’s campaign chairman.

“In the wake of this election, it’s pretty clear that the U.S. does not have the tools to combat this massive disinformation machinery that the Russians are running,” Murphy said in an interview.

The measure approved Wednesday is aimed at foreign information sources, not ones based in the United States.

The effort would expand the State Department’s Global Engagement Center, which focuses on combating propaganda and recruitment by the Islamic State and other violent extremist groups, and would draw support from the Defense Department, intelligence agencies, the U.S. Agency for International Development and the Broadcasting Board of Governors.

The measure also would create a grant program to help foster civil society and independent journalism in countries targeted with propaganda campaigns by Russia and other foreign powers, including China.

One independent researcher into Russian propaganda efforts, Clint Watts, said he worried that the Global Engagement Center is poorly suited to lead a broad U.S. government response that spans several departments. He complained that the resulting effort may be unfocused and overly bureaucratic.

“It’s the opposite of what we need,” said Watts, a former FBI agent and a fellow at the Foreign Policy Research Institute. “We need to be moving quickly, nimbly.”

The Senate Intelligence Committee, meanwhile, has approved language in the fiscal year 2017 intelligence authorization bill calling for new executive branch efforts to combat what it characterized as “active measures” by Russia to manipulate people and governments through front groups, covert broadcasting or “media manipulation.”

“There is definitely bipartisan concern about the Russian government engaging in covert influence activities of this nature,” Sen. Ron Wyden, D-Ore., a member of the Senate Intelligence Committee, said in a statement. “If you read section 501 of this year’s intelligence authorization bill, it directs the President to set up an interagency committee to ‘counter active measures by Russia to exert covert influence over peoples and governments.’ So that shows you that senators from both parties are clearly concerned about Russian covert influence efforts.”

Six Democrats on the Senate Intelligence Committee and King, an independent from Maine, called on Obama to publicly disclose more information about Russian government activity during the election.

“We believe that there is additional information concerning the Russian government and the U.S. election that should be declassified and released to the public. We are conveying specifics through classified channels,” said a letter from the senators dated Tuesday.