Sudan's President Omar al-Bashir is in Tripoli on his first visit since the fall of Muammar Gaddafi, in a bid to restore relations which soured in the last years of the Libyan dictator.
Airport sources said President Bashir arrived with a high-level delegation for a two-day visit.
Khartoum had accused Gaddafi of supporting Sudanese rebels in the western region of Darfur.
In return, President Bashir openly said he supported Libyan rebels in their 2011 uprising, providing them with weapons and money.
President Bashir, like Gaddafi - who was killed in October - is wanted by the International Criminal Court for crimes against humanity for his role in orchestrating a bloody crackdown against the Darfur rebels.