US transgender soldier Chelsea Manning has posted a portrait photograph of her “new look” with short-cropped hair.

It is the first image of the former army private after being freed from a Kansas military prison and a 35-year sentence for leaking classified materials.

The transgender soldier formerly known as Bradley Manning took to Twitter and Instagram on Thursday, posting a portrait photograph of her with short-cropped hair, bright red lipstick and a dark outfit with a plunging neckline.

The 29-year-old Oklahoma native included the caption, “Okay, so here I am everyone.”

Ms Manning was released early on Wednesday from confinement at Kansas’ Fort Leavenworth, after having served seven years behind bars for giving classified materials to anti-secrecy website WikiLeaks.

Manning relished her newfound freedom, posting on social media photos of her lunch – “So, (I’m) already enjoying my first hot, greasy pizza,” she declared of the slice of pepperoni – and her feet in sneakers, with the caption, “First steps of freedom!!”

“I’m figuring things out right now – which is exciting, awkward, fun, and all new for me,” Manning said by email hours after being released.

“I am looking forward to so much! Whatever is ahead of me is far more important than the past,” added Manning, who was convicted in 2013 of 20 counts, including six Espionage Act violations, theft and computer fraud. She was acquitted of the most serious charge of aiding the enemy.

Ms Manning and her lawyers have refused to divulge her post-prison whereabouts or immediate plans citing security reasons, but she had previously tweeted that she planned to move to Maryland where she has an aunt.

The army is allowing her to live where she pleases as she is still on active duty but under a special unpaid status.

President Barack Obama announced in January he would commute Manning’s sentence to about seven years, including the time she spent locked up before being convicted.

It drew strong criticism from members of Congress and others, with Republican House Speaker Paul Ryan calling the move “just outrageous.”

On social media on Wednesday, people either hailed her as a courageous hero or denounced her as a traitor.

In a statement last week – her first public comments since Obama wiped away her remaining sentence – Manning thanked him and said letters of support from veterans and fellow transgender people inspired her “to work toward making life better for others.”

–  with AAP