Whistleblower Chelsea Manning said she sees a lot of similarities between prison and the modern world, as she spoke during her first UK public appearance.

The former US intelligence analyst served seven years of a 35-year sentence for leaking hundreds of thousands of classified government documents.

In the final days of his White House term, former American president Barack Obama commuted the transgender soldier’s sentence.

Speaking at an event organised by the Institute of Contemporary Arts, the 30-year-old said she is “constantly bombarded” by reminders of how drastically different the world is now than before she went to prison.

“This whole notion that you get out of prison and you are free, now turned out to be a bit of a downer in that sense,” she told those gathered for the event at the Royal Institute in central London on Monday.

“Because, what happened, we really built this large, big prison, which is the United States, in the meantime – it was already happening, it just really intensified.

“You think about the surveillance systems, the cameras, or the police presence, and you think about the fact that we have walls around our country, and that is very much the same thing that is inside a prison.

“I see a lot of similarities between the world out here and the world that was in there.”

Manning was arrested in 2010 and convicted in 2013 of six violations of the US espionage act for leaking 700,000 secret military and State Department documents.

The trove, which included classified battlefield videos, was one of the biggest breaches of intelligence in US history.

She acknowledged leaking the files while working in Iraq, but protested that she had acted to raise awareness of the impact of US military action on innocent civilians.

Then known as Private Bradley Manning, she later underwent gender transition in jail.

Manning, whose father is American, was born in Oklahoma but moved to Haverfordwest in Pembrokeshire, West Wales, just before she turned 14 in 2001 following her parents’ divorce.

She attended Tasker Milward comprehensive school and still has family and friends in the area.

Asked by the Press Association whether she regrets her decision to leak the files, she said: “I did what I did because of what I had available to me.

“In that timeframe, what I knew and what I understood, and the background that I had and who I am, the values set that I have, and also the short time that I had to make decisions.

“The way I see it, is I don’t go back in time… what I really try to tell people is that if I had done anything differently it would have been a completely different person.”

Following her release from prison Donald Trump took to Twitter to describe Manning as a “traitor” who should never have been released.

Pressed for her response to President Trump’s statement at the time, Manning said to applause: “Well, here I am.”