A British teenager who joined the Islamic State group in Syria in 2015 said yesterday she was shocked by a government decision to revoke her citizenship.

Shamima Begum, who now wants to return home after giving birth in a refugee camp in Syria last weekend, said the order was "unjust".

"I am a bit shocked," she told ITV News after learning of the move which was announced in a letter Tuesday from Britain's interior ministry to her mother in London.

"It's a bit upsetting and frustrating. I feel like it's a bit unjust on me and my son."

Begum's fate has stirred controversy since she and two friends fled her east London home to join the terror network four years ago when she was aged just 15.

The case highlights a dilemma facing many European countries, divided over whether to allow jihadists and IS sympathisers home to face prosecution or barring them over security concerns as the so-called "caliphate" crumbles.

She added that interior minister Sajid Javid was intent on prioritising "the safety and security of Britain and the people who live here".