President Donald Trump has fired the director of the Cybersecurity and Infrastructure Security Agency, after the agency spent weeks debunking election fraud claims on its “Rumor Control” page. Chris Krebs led the agency as its first director after Trump nominated him for the role in February 2018.

During that time, CISA had been responsible for coordinating election security among officials in all 50 states, focusing on improvements at the local and county level. That’s included measures like installing sensors in election county networks to detect potential cyberattacks and hosting virtual rooms to share information about threats.

The election security effort also meant fighting disinformation and debunking rumors that would often mirror the Trump administration’s comments. CISA launched its Rumor Control page on Oct. 20 as part of its ongoing effort to debunk election fraud claims, which it continues to update well after the election was called for President-elect Joe Biden.

Trump hasn’t accepted the results of the election and continues to claim that the results were due to fraud, throwing out various theories like votes being cast by dead people and the voting tally being hacked.

The president announced Krebs’ firing in a tweet on Tuesday.

On Twitter, Krebs responded to the news and wrote, “Honored to serve. We did it right.”

CISA didn’t respond to a request for comment. Jack Cable, a security researcher and an election security technical advisor at CISA, said on Twitter that it was an honor to work under Krebs.

“Election security is not political,” Cable said. “Director Krebs should be commended for his nonpartisan approach to protecting democracy and ensuring a secure 2020 election.”

The Rumor Control page has been directly contradicting many of Trump’s claims, and while Krebs hasn’t directly challenged the president’s remarks, he has debunked the election fraud hoaxes that the president supports.

White House officials had asked for edits to the Rumors Control page, and CISA refused to do so, Reuters reported on Nov. 12 The White House was specifically frustrated by the debunk of the “Hammer and Scorecard” conspiracy theory, which claimed Democrats were using a supercomputer and software to steal the election.

Krebs’ termination leaves a void at the US’s agency responsible for election security, which many officials credit for a smooth Election Day free from cyberattacks.

The firing has led lawmakers to speak out against Trump’s decision, praising Krebs’ work on election security and CISA’s refusal to change its Rumor Controls page.

House Speaker Nancy Pelosi called Krebs a “deeply respected cybersecurity expert” and said Trump’s actions undermines US democracy.

“Director Krebs is a deeply respected cybersecurity expert who worked diligently to safeguard our elections, support state and local election officials and dispel dangerous misinformation,” Pelosi said. “Yet, instead of rewarding this patriotic service, the President has fired Director Krebs for speaking truth to power and rejecting Trump’s constant campaign of election falsehoods.”

The House Homeland Security committee’s chairs also said that Trump firing Krebs “makes America less safe.”

“Chris Krebs has done a great job protecting our elections,” Sen. Mark Warner, a ranking member on the Senate Intelligence committee, said in a tweet on Nov. 12. “He is one of the few people in this administration respected by everyone on both sides of the aisle. There is no possible justification to remove him from office.”

He followed up on Tuesday after Trump’s announcement, raising concerns about destabilizing the US government during a presidential transition period.

“Chris Krebs is an extraordinary public servant and exactly the person Americans want protecting the security of our elections,” Warner said in a statement on Tuesday. “It speaks volumes that the president chose to fire him simply for telling the truth.”

On Monday, Sen. Ron Wyden, a Democrat from Oregon, criticized Trump for his remarks about election infrastructure security, pointing out that the president didn’t pay attention to the issue until after he lost.

After Trump announced Krebs’ firing, House Intelligence Committee Chairman Adam Schiff commended the CISA director’s role in election security, noting that the agency provided vital support to state and local election officials.

“Instead of rewarding this great service, President Trump is retaliating against Director Krebs and other officials who did their duty. It’s pathetic, but sadly predictable that upholding and protecting our democratic processes would be cause for firing,” Schiff said in a statement.

The agency also coordinated with social networks like Facebook, Twitter and YouTube on election misinformation leading up to the election. Nathaniel Gleicher, Facebook’s head of cybersecurity policy, thanked Krebs for his work after Trump announced the termination.

“It has been an honor to work with you and your team — you’re the best in the business, and we are all in your debt,” Gleicher said in a tweet.