Washington (AFP) - President Barack Obama Wednesday defended his decision to commute the sentence of transgender army private Chelsea Manning, who was jailed for 35 years for handing classified US documents to WikiLeaks.

Obama was addressing his final presidential news conference a day after he pardoned 64 people and commuted the sentences of 209 others -- including Manning, who will now be released in May -- in one of his last acts in office.

"With respect to Chelsea Manning I looked at the particulars in this case the same way I have with the other commutations I have done and pardons I have done and felt in light of all the circumstances that commuting her sentence was entirely appropriate," Obama said.

Manning was convicted in August 2013 of espionage and other offenses, after admitting to the leak of 700,000 sensitive military and diplomatic documents.

"It has been my view that given she went to trial, that due process was carried out, that she took responsibility for her crime, that the sentence that she received was very disproportionate relative to what other leakers had received and that she had served a significant amount of time, that it made sense to commute and not pardon her sentence," Obama said

"Let's be clear, Chelsea Manning has served a tough prison sentence," the president added. "I feel very comfortable that justice has been served."

The cache of documents leaked by Manning included military logs from wars in Iraq and Afghanistan and diplomatic cables offering sensitive -- and often embarrassingly blunt -- assessments of foreign leaders and world events.

Manning pleaded guilty and was sentenced by military court martial. She has since been held in an all-male prison, at times in solitary confinement, and has attempted to commit suicide twice.

Activists had argued her sentence is excessive and point to the psychological frailty of the transgender soldier.