Facebook said on Thursday it was referring its decision to indefinitely suspend the accounts of former U.S. President Donald Trump to its independent oversight board. 

Trump will remain suspended while the board, a recently created body that can overrule the company's decisions on content, reviews the decision. 

Facebook blocked Trump's access to his Facebook and Instagram accounts over concerns of further violent unrest following the January 6 storming of the U.S. Capitol by the former president's supporters. 

"I'm very confident of our case," said Facebook's head of global affairs, Nick Clegg. "I'm very confident that any reasonable person looking at the circumstances in which we took that decision and looking at our existing policies will agree."

"But of course this is a decision which has had reverberations around the world," he added. It is the first time the company has blocked a current president, prime minister or head of state. 

Facebook did not ask for an expedited review, so the board, which said on Thursday it had accepted the case, will have a maximum of 90 days to make a ruling and for Facebook to act on it. An oversight board spokesperson said it would likely be sooner than that. 

The administrators of Trump's Facebook page will have the option to submit a written statement challenging Facebook's decision. 

Facebook had also asked the board to provide recommendations on when political leaders can or should be blocked. Facebook does not have to act on this recommendation, unlike the board's case decision which is meant to be binding. 

The oversight board, which currently has 20 members, was created by Facebook in response to criticism of its handling of problematic content. 

"That's why we're here, to not leave these decisions to the leadership of Facebook but actually use the oversight board to look at this in a principled way," said Helle Thorning-Schmidt, a board co-chair and the former Danish prime minister. 

The board, which has been criticized for its delayed start and limited remit, has not yet ruled on its first batch of cases. 

Facebook said when it suspended Trump that the block would last at least until the end of Trump's presidential term and perhaps indefinitely. Trump's term expired on Wednesday when Joe Biden was sworn in as president. 

Twitter has suspended Trump permanently.