Libyan Prime Minister Abdel Rahim al-Kib is in Mauritania to push for the extradition of Muammar Gaddafi's ex-spy chief, Abdullah al-Senussi.
Ousted Libyan dictator Muammar Gaddafi's former spy chief and brother-in-law was arrested in Mauritania back in March after he flew into the Mauritanian capital Nouakchott from Casablanca, Morocco, on a forged Malian passport.
Mauritian officials have charged Abdullah al-Senussi with falsifying documents and entering the West African nation illegally.
On Tuesday, Mustafa Abdel Jalil, the head of Libya's National Transitional Council (NTC), demanded Senussi's extradition from Mauritanian President Mohamed Ould Abdel Aziz in a phone call.
Al-Senussi is also wanted by the International Criminal Court (ICC) for being an "indirect perpetrator of crimes against humanity, of murder and persecution based on political grounds" in the eastern Libyan city of Benghazi.
But officials in the post-revolution Libya want the Gaddafi ally, nicknamed the butcher, for allegedly playing a key role in the killing of more than 1,200 detainees at Tripoli's Abu Salim prison in 1996.
In addition, Al-Senussi is sought by the authorities in France after a court there sentenced him to life in prison for his involvement in a 1989 bombing of a French airliner over Niger. The attack claimed the lives of 170 people, including 54 French nationals.
Senussi has also been linked to the 1988 bombing over Lockerbie, Scotland of a PanAm jet that killed 270 people.