Germany and the United Nations hope to persuade Russia, Turkey, the United Arab Emirates and Egypt to push their opposing camps to agree on a lasting truce in Tripoli, home to the internationally recognised government.
Erdogan made his remarks in a column published on the Politico website on Saturday, ahead of a summit in Berlin on Sunday that will try to stabilise the country
Both of Libya's warring factions accused each other of violating a ceasefire proposed by Turkey and Russia, as fighting continued around the capital, Tripoli, on Sunday.
Turkey's decision to send the advisers and technical experts responded to a request by Prime Minister Fayez al-Serraj's GNA, which Ankara backs against forces allied to veteran commander Khalifa Haftar.
"This decision seriously undermines the international community's efforts to find a peaceful, political solution to the Libyan conflict"
Libya's internationally recognised Government of National Accord (GNA) has been fending off a months-long offensive by General Khalifa Haftar's forces in eastern Libya, which have been supported by Russia, Egypt and the United Arab Emirates.
Kavala, who faces life in jail if convicted, denies the allegations. Fifteen other defendants are on trial along with Kavala, who is currently the only one in jail. Their trial was adjourned until Jan. 28.
Turkey backs Fayez al-Serraj's Government of National Accord (GNA) in Libya, which has been torn by factional conflict since 2011, and has already sent military supplies to the GNA despite a United Nations arms embargo, according to a report by U.N. experts seen by Reuters last month.