Erdogan vows military support to Libya amid rising tensions
His comments come a day after the Turkish parliament ratified a security and military cooperation deal signed between Ankara and Tripoli last month.
"We will evaluate all kinds of military support including ground, marine and air options if necessary," Erdogan said during a speech in the northwestern province of Kocaeli.
Although Erdogan has said Turkey is willing to send troops to Libya, the government must seek a separate mandate from the Turkish parliament to send forces to fight there.
Turkey supports the UN-recognised Government of National Accord (GNA) based in Tripoli in the struggle against eastern Libya strongman Khalifa Haftar.
Haftar is backed by Saudi Arabia, Egypt and the United Arab Emirates, countries with whom Turkey has tense or limited relations.
Forces loyal to Haftar said on Saturday they had seized a Turkish ship to search its cargo, but Ankara has made no official comment on the claim.
Turkey was criticised by Greece, Cyprus, and Egypt over the military deal with Libya and a separate maritime jurisdiction agreement, also signed in November.
Part of the deal sets a maritime boundary between the two countries which Greece says does not take into account the island of Crete. On Sunday, the Greek foreign minister visited eastern Libya for talks with the Haftar-allied unrecognised Libyan government, which is based in Tobruk.
But Erdogan on Sunday said Turkey would not "take a step back" from any Libya agreement despite opposition from Greece and Cyprus over maritime boundaries.
"Those who are against us have no awareness of rights, law, justice, ethics or mercy," he added.