Libyan leader Muammar Gaddafi has promised to meet with the Russian president's point man on Africa, Mikhail Margelov said on Thursday.
Margelov met with Libyan Prime Minister Al-Baghdadi Ali Al-Mahmoudi earlier in the day.
"A meeting with Gaddafi was not planned this time but Prime Minister Mahmoudi conveyed Col. Gaddafi's request to meet me when I come next," Margelov said.
He did not say when he would visit next.
Margelov said he had surmised from his conversation with the prime minister that "there is one red line" for the Libyan leadership that "it is not prepared to cross - namely, Muammar Gaddafi's political fate."
"From Tripoli's perspective, there can be no question about Muammar Gaddafi's leaving the political scene today," the Russian envoy said.
However, Gaddafi's son, Saif al-Islam, said earlier in the day Tripoli was ready to hold free elections and allowed the possibility of Gaddafi losing them.
In an interview with Italy's Corriere della Sera, al-Islam said that if his father's opponents won the election, Gaddafi would not leave Libya "because he was born here and this is where he will die."
Margelov also met with Foreign Minister Abdel Ati Al-Obeidi to discuss ways out of the deepening political crisis in the North African country.
Tripoli would like to see a joint AU-UN mission to monitor the disarmament process on both sides, Margelov said citing Obeidi.
The Libyan authorities are calling for an immediate ceasefire, after which a broad dialog about the country's future could begin, Obeidi said.
Last week, Margelov, who is also chairman of the foreign affairs committee in the Russian parliament's upper house, visited the Libyan opposition stronghold city of Benghazi where he held talks with the leaders of the Transitional National Council (TNC).
The envoy expressed hope that he would be able to present a "roadmap" for resolving the four-month conflict in Libya following his talks with both the opposition and Gaddafi's representatives.