Timothy Omotoso was accused of raping several of his congregants in a trial that gripped the country.
President Tinubu said he wishes to boost Nigeria's oil output and refining capability.
"We will develop relations between our countries and are waiting for proposals from the Namibian side."
They were among 37 people sentenced to death last September by a military court.
Relations between Kiir and Machar, who have dominated South Sudan's politics for decades, remain strained.
Once the commercial heart and seat of Sudan's government, Khartoum is now a burnt-out shell.
Officers say they identified the individuals through social media posts and a WhatsApp group.
The girl was reported missing by her family in the semi-autonomous region of Puntland last September.
The president warned that such behaviour risked exposing state secrets and delayed service delivery to the public.
