The Department of Justice has dropped the criminal case against Michael Flynn, President Donald Trump's ex-national security adviser.

The decision to initiate proceedings was made by former special prosecutor Robert Mueller, who led the Russian investigation. The case was decided to be dismissed even though representatives of the prosecutor's office over the past three years have claimed that Flynn lied in an interview with FBI agents in January 2017 about his talks with the former Russian ambassador to the US Sergei Kislyak, Voice of America reported.

On Thursday, Trump said Flynn is "innocent," CNN reported. 

"I'm very happy for General Flynn, he was a great warrior, and he still is a great warrior. Now in my book is an even greater warrior," Trump said.