Libyan Prime Minister Abdel Rahim al-Kib arrived Wednesday in Mauritania, where he is expected to push for the extradition of Moamer Kadhafi's ex-spy chief, the official AMI agency reported.
Abdullah al-Senussi, feared former right hand man of the slain Libyan leader, was arrested in March in Mauritania and charged two months later for using forged travel documents to illegally enter the country.
The head of Libya's National Transitional Council (NTC), Mustafa Abdel Jalil, reiterated his administration's demand for Senussi's extradition in a phone call to Mauritanian President Mohamed Ould Abdel Aziz on Tuesday.
In June 2011, the International Criminal Court issued a warrant for Senussi saying he was an "indirect perpetrator of crimes against humanity, of murder and persecution based on political grounds" in the eastern Libyan city of Benghazi.
Benghazi was the birthplace of a revolt that started in February 2011 and eventually put an end to more than four decades of dictatorship in Libya and led to the death of Kadhafi and arrest of several of his allies.
Senussi is the target of another international arrest warrant after a Paris court sentenced him in absentia to life imprisonment for involvement in the downing of a French UTA airliner over Niger in September 1989.
The plane was carrying 170 people from Brazzaville to Paris via N'Djamena.
Libya last month obtained the extradition of Kadhafi's last prime minister Baghdadi al-Mahmudi from Tunisia, where he had been held since last year.
Mahmudi's lawyer and rights groups had voiced concerns that Libya's ex-rebels had not offered sufficient guarantees that former regime stalwarts would be given a fair trial in Libya.