Erdogan, Libya's Sarraj convene in closed-door meeting as tensions boil
The closed-door meeting, which was not on Erdogan's official agenda, took place in Istanbul's Ottoman-era Dolmabahce Palace, the Turkish presidency said without giving details.
During the previous meeting between the two men in Istanbul on November 27, the two countries agreed a deal on security and military cooperation, as well as maritime jurisdiction.
The deal came despite calls from the Arab League - which includes Libya - to end cooperation with Turkey in protest at its military offensive against Kurdish forces in Syria.
Libya has been mired in chaos since a NATO-backed uprising that toppled and killed dictator Muammar Gaddafi in 2011.
Read also: Turkish parliament expected to approve controversial military pact with Libya
Saudi Arabia, Egypt and the UAE back Khalifa Haftar, a military strongman in eastern Libya who launched an offensive in April in a bid to seize Tripoli from fighters loyal to the Government of National Accord (GNA), of which Sarraj is the prime minister.
Turkey and Qatar openly support the UN-recognised GNA.
The November military deal was introduced in the Turkish parliament on Saturday.
The maritime part of the deal expands Turkey's continental shelf in the Eastern Mediterranean. This is particularly important given the recent discovery of vast gas reserves that has triggered an exploration scramble between adjacent states and international oil companies.
The Turkey-Libya agreement was strongly condemned by several countries, including Greece and Cyprus.
Erdogan declared on Tuesday that Turkey is prepared to send troops into Libya if requested.
When asked about sending troops during a television interview late on Sunday, he said that "Turkey alone will decide what initiative to take".
"I have already said that we were ready to provide all sorts of help to Libya," Erdogan added.
In another sign of the Turkey-Libya rapprochement, Ankara announced on Saturday that Libyans younger than 16 or older than 55 would be allowed to enter Turkey without visas.
Read also: 'I will sink your ships myself': Haftar's navy commander threatens Erdogan
Strongman Haftar on Thursday announced a "decisive battle" to wrest Tripoli from the GNA government.
GNA Interior Minister Fathi Bashagha responded by saying his government was ready "to push back any mad attempt by the Haftar putsch leader".