Turkey backs the GNA, providing military support following an April 2019 offensive on Tripoli by rival strongman Khalifa Haftar, and helped turn the tide in the conflict earlier this year.
The GNA earlier this year repelled a deadly offensive on Tripoli by Haftar.
Haftar has enjoyed support from Egypt, Saudi Arabia, the United Arab Emirates and Russia.
The North African country descended into chaos after a Western-backed uprising toppled dictator Muammar Gaddafi.
“President Erdogan stated that Turkey would continue to stand by Libya in full solidarity and strengthen relations with the Goverment of National Accord, the only legitimate representative of Libya,” the presidency said.
The last meeting in Istanbul came less than a month ago when Sarraj visited the city on September 6.
The Tripoli-based government and a parliament in the eastern city of Tobruk linked to Haftar agreed in August on a ceasefire and elections by March.
After recent talks between the two sides in Morocco, Sarraj said he was willing to step down as a new government comes together.
Last month, Erdogan said Sarraj’s resignation “saddened us”.
Turkey signed two deals with the Tripoli government on security and maritime boundaries.