United States President Donald Trump on Tuesday fired a top election official who rejected his claims of fraud in the 2020 presidential polls.

Trump announced the decision on Twitter. “Votes from Trump to Biden, late voting, and many more,” he said. “Therefore, effective immediately, Chris Krebs has been terminated as Director of the Cybersecurity and Infrastructure Security Agency.”

The US president said that Krebs’ recent statement on the security of the presidential election was highly inaccurate, “in that there were massive improprieties and fraud – including dead people voting, Poll Watchers not allowed into polling locations, “glitches” in the voting machines which changed.” Both of Trump’s tweets were flagged by the microblogging site.

Krebs, on the other hand, defended his stance. “Honored to serve,” he tweeted. “We did it right. Defend Today, Secure Tomorrow.”

In the run-up to the elections, the top official had on several occasions contradicted Trump’s false claims about mail-in ballots, though not in an outright manner, according to CNN. He has been more vocal about Trump’s claims recently, continuously posting fact-checks of the conspiracy theories floated by Trump.

On Sunday, Trump backtracked after acknowledging for the first time that Biden had won the presidential election. He claimed again that the election was rigged. “He only won in the eyes of the FAKE NEWS MEDIA,” Trump tweeted. “I concede NOTHING! We have a long way to go. This was a RIGGED ELECTION!”. The president’s tweet was flagged by the microblogging site, like many others, alleging election fraud.

The US president’s remarks came after the media projected results in two uncalled states. Trump was projected to win North Carolina, according to The Washington Post, while President-elect Biden was projected to secure Georgia. With this, Biden was projected to get 306 electoral votes, while Trump would bag 232.

Last week, the Krebs-led Cybersecurity and Infrastructure Security Agency had also rejected Trump’s claims of election fraud and said that the 2020 elections were the “most secure in American history”.

Trump has refused to commit to a peaceful transfer of power to President-elect Joe Biden and filed several lawsuits in the last few days to challenge the election outcome. He has continued to claim that there was a multi-state conspiracy by the Democrats to stop him from achieving a second term.

Earlier this month, Trump had fired Defence Secretary Mark Esper and Executive Director of the US’ Global Change Research Program Michael Kuperberg.