"I call on my brother Khalil to rejoin the Doha negotiations because there is no other option but to enter the peace process," Kadhafi told RFI in an exclusive interview.
Ibrahim is the head of the Justice and Equality Movement [JEM], the most heavily armed group in the Darfur region. He has been in Libya since May 19, after he was turned back by authorities in Chad as he sought to enter Darfur.
The JEM suspended peace talks at the start of May involving Qatar, the African Union and the United Nations, and resumed hostilities.
Libya's decision to shelter Ibrahim has angered Khartoum, which has sought his extradition and asked Interpol's help in arresting him.
Kadhafi said the presence of Ibrahim was a "dilemma" for Tripoli, adding that he had been banned from giving orders or issuing statements while in the country.
"I am not protecting one party against another, my role is not to protect but to make a reconciliation between all the parties involved," said Kadhafi.
Kadhafi said a meeting had taken place in Libya between Ibrahim and Chad's President Idriss Deby Itno, without giving further details.