Chelsea Manning is an "ungrateful traitor" who "should never have been released from prison", President Donald Trump has said on Twitter. Manning, who was convicted of leaking documents to Wikileaks in 2010, recently had her sentence commuted by former President Barack Obama. The transgender US Army private, born Bradley Manning, said in an op-ed that Mr Obama's legacy was not bold enough. Mr Trump took to Twitter to criticise her for calling Mr Obama a weak leader. "Ungrateful TRAITOR Chelsea Manning, who should never have been released from prison, is now calling President Obama a weak leader. Terrible!" he tweeted.