"The living conditions in the camps are extremely bad and dangerous. These Norwegian children have been living for a long time in these camps where no children should have to live", Foreign Minister Anniken Huitfeldt said in a statement.

The two sisters of Somali origin clandestinely left Norway for Syria in late 2013, aged 16 and 19, to join a popular uprising against the regime of President Bashar al-Assad, as they would later explain in an e-mail exchange.

Norwegian writer Asne Seierstad recounted their experiences in a book.

The sisters, now aged 29 and 25, are between them mothers to three daughters born from partnerships with Islamic State fighters, according to Norwegian paper Verdens Gang.

All five are set to be taken to Norway from the Al-Roj camp which is under Kurdish administration in northeastern Syria.

"The two women themselves asked for assistance to return with their children (and) know they will be arrested on arrival in Norway," said Huitfeldt.

The situation of the sisters has been much discussed in Norway, as have similar cases involving youngsters from other European countries who made their way to Syria.

One such case was that of Shamima Begum, 23, who was stripped of her British citizenship after travelling to Syria as a teen to marry an IS fighter and who last month lost her legal battle to reverse the decision.

Huitfeldt noted that the United States as well as the UN and Kurdish authorities have been backing repatriation in such cases, citing instability in the region housing the refugees.

Norway in 2020 repatriated a woman from Syria with IS links as one of her children was seriously ill.