Secretary of State Mike Pompeo said Tuesday that a debunked conspiracy theory pursued by President Trump accusing Ukraine, not Russia, of interfering in the 2016 presidential election by hacking the network of the Democratic National Committee is a worthy subject of investigation.

In a news conference at the State Department, Pompeo was asked if the United States and Ukraine should investigate the conspiracy theory, which several former senior Trump officials have called a “fictional narrative” with “no validity.”

“Anytime there is information that indicates that any country has messed with American elections, we not only have a right but a duty to make sure we chase that down,” Pompeo told reporters.

Pompeo, who previously served as the director for the CIA, said he learned during his time leading the nation’s premier spy service that “there were many countries that were actively engaged in trying to undermine American democracy, our rule of law, the fundamental understandings we have here in the United States.”

Trump’s interest in the fringe theory came into prominence following the release of the rough transcript of his July 25 phone call with Ukraine’s president, in which Trump asked if Ukraine could “find out what happened with this whole situation with Ukraine” and “CrowdStrike.”

The theory, which former White House official Fiona Hill last week said is “being perpetrated and propagated by the Russian security services,” is that Ukrainians actually hacked into the DNC’s networks in 2016 and framed Russia for the cyber-meddling.

Advocates of the theory charge that the Internet security firm CrowdStrike, which first investigated the DNC hack in June 2016, is led by a Ukrainian national who assisted in framing Russia with the election interference. They charge that the server was later taken to Ukraine.

Trump repeated this idea on Fox News last week. “They gave the server to CrowdStrike, or whatever it’s called, which is a company owned by a very wealthy Ukrainian, and I still want to see that server.”

CrowdStrike is not run by a wealthy Ukrainian. It is a California-based company co-founded by a Russian-born American tech executive. Former Trump officials have expressed exasperation with how this theory continues to be perpetuated.

“It’s not only a conspiracy theory, It is completely debunked,” Tom Bossert, a former homeland security adviser in the Trump administration, said in September. “At this point, I am deeply frustrated with what [Trump’s personal attorney Rudolph W. Giuliani] and the legal team are doing and repeating that debunked theory to the president.”

“It sticks in his mind when he hears it over and over again, and for clarity let me just repeat that it has no validity,” Bossert added.

Hill, who recently stepped down from the Trump administration, said these conspiracy theories weren’t just false but also “harmful, even if they’re deployed for purely domestic political purposes.”

“President Putin and the Russian security services operate like a super PAC. They deploy millions of dollars to weaponize our own political opposition research and false narratives,” she said. “When we are consumed by partisan rancor, we cannot combat these external forces as they seek to divide us against each other, degrade our institutions and destroy the faith of the American people in our democracy.”

During the 2016 elections, some Ukrainian officials criticized Trump’s remarks about Russia’s seizure of the Crimean peninsula, including a former Ukrainian ambassador to the United States, Valeriy Chaly, who penned an op-ed in August of that year. While it is unorthodox for a foreign diplomat to criticize a major candidate in an American election, Hill and other analysts said such moves are not equivalent to Russia’s concerted and top-down intervention in the U.S. election

Pompeo, however, without specifically endorsing the server conspiracy theory, suggested that any accusations related to the 2016 election are worth pursuing.

“To protect elections, America should leave no stone unturned,” Pompeo said.