Mr Wallace told the BBC: "Actions have consequences.
"I am not putting at risk British people’s lives by going to look for former terrorists.
"We have a duty to the UK citizens here to make sure we take measures to keep the safe. We have to mitigate the threat if she comes back."
He said that "as a British citizen she has the right to home here" but he added: "Anyone who goes to fight for Isis, a dreadful, horrendous group, should expect to be interviewed and potentially prosecuted."
New terror laws which came into action recently can land offenders who travel to certain areas in Syria with up to ten years in prison.
I’ll do anything required just to be able to come home and live quietly with my child
Shamima Begumschoolgirl who left for Syria in 2015
She could also face action if she's been a part of any crimes while she's been out there, or if security services can prove she still supports Isis now.
Theresa May's spokesperson said today: "Anyone who has travelled to Syria for whatever reason has put themselves in considerable danger and also potentially poses a very serious national security risk to the United Kingdom.
"Whatever the circumstances of an individual case, we have to, and will, protect the public."
Amira Abase's Dad Hussen told The Sun Online this morning: "Give them some kind of teaching. As a teenager, you can do anything - I did too.
"They are not a threat."
Police chiefs this morning said it would be incredibly costly for local forces to keep her safe if she were allowed back into the country - as both far-right fanatics and Isis supporters could put her at risk.
And her child could be taken off her by social services too if she was found to be a risk to them.
Shamima's two other kids have died in Syria, she revealed in her interview.
Ex-Prevent lead Sir Peter Fahy said earlier she would be a "lightening rod" for attention and said she could "attract the focus of extremists on both sides".
He added: "If the woman was showing complete remorse, it would be different."
Footage 'of British I.S. schoolgirls'
The teen was discovered by a in a camp filled with refugees escaping the battle for the final ISIS stronghold.
She told him she had been married to a Dutch fighter and enjoyed a “normal” life, but he is said to have surrendered himself to Syrian fighters and she is believed to be a widow.
"I know what everyone at home thinks of me as I have read all that was written about me online," the teen said.
"But I just want to come home to have my child. I’ll do anything required just to be able to come home and live quietly with my child."
She insisted: “I’m not the same silly little 15-year-old schoolgirl who ran away from Bethnal Green four years ago and I don’t regret coming here."
Bengum used her sister's passport to flee the UK back in 2015 with two pals.
The trio flew to Turkey and crossed the border into Syria later on.
Last night her family begged for her to be allowed back into the UK and said she was vulnerable as she was pregnant.
Her sister Renu yesterday told ITV News: "I’m so relieved that my sister has been found, safe and sound.
"We are aware that she has been trying to get out.”
SHAMIMA Begum, Kadiza Sultana and Amira Abase are thought to have crossed into Syria from Turkey to join Islamic State
In 2018, it was revealed that almost 400 Brit jihadis who fought for bloodthirsty ISIS in Syria are back in the UK.
But shockingly just one in ten have been prosecuted for "direct action they've carried out in Syria".
Around 15 per cent of the 850 Brits believed to have travelled to Syria or Iraq have died.
The Home Office says every person who returns is questioned by police and an assessment made over whether they are a threat to Britain.
However few have been prosecuted.
The Counter-Terrorism and Border Security Bill is currently going through Parliament, after its third reading in the House of Lords.
This could make travelling abroad to join terror groups an offence which carries a penalty of ten years in prison.
Security Minister Ben Wallace said: "The UK advises against all travel to Syria and parts of Iraq. Anyone who does travel to these areas, for whatever reason, is putting themselves in considerable danger.
"Everyone who returns from taking part in the conflict in Syria or Iraq must expect to be investigated by the police to determine if they have committed criminal offences, and to ensure that they do not pose a threat to our national security.
"There are a range of terrorism offences where individuals can be convicted for crimes committed overseas and we can also use Temporary Exclusion Orders to control an individuals' return to the UK."
Pregnant jihadi schoolgirl Shamima Begum who fled UK to join ISIS begs to come home to have fanatic’s baby after escaping terror group
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