It means the president will be unable to post on Facebook and Instagram until after the transition of power to Joe Biden on 20 January.
The social network had originally imposed a 24-hour ban after his supporters attacked the US Capitol.
Facebook's chief Mark Zuckerberg wrote that the risks of allowing Trump to post "are simply too great".
In a video posted to Facebook, Twitter and YouTube, Trump told the rioters attacking the seat of government "I love you" before telling them to go home. He also repeated false claims about election fraud.
The largest social networks each took action against the president's accounts in the wake of the violence.
Zuckerberg said Facebook had removed the president's posts "because we judged that their effect - and likely their intent - would be to provoke further violence".
He said it was clear Trump intended to undermine the transfer of power to President-elect Joe Biden.
"Therefore, we are extending the block we have placed on his Facebook and Instagram accounts indefinitely and for at least the next two weeks until the peaceful transition of power is complete," he wrote.