Turkish Prime Minister Ahmet Davutoglu travelled into Syria on Sunday to visit a relocated historic tomb inside the country, his office said.
The trip, which was not announced in advance, is the first such visit by a Turkish political leader to the tomb of Suleyman Shah, grandfather of the Ottoman empire's founder Osman I, just 200 metres (650 feet) from the Turkish border inside Syrian territory.
Davutoglu visited Turkish troops who are permanently stationed at the tomb, which now lies in the settlement of Eshme and is easily visible from Turkish territory, his office said.
In February, hundreds of Turkish soldiers staged an unprecedented incursion deep inside Syrian territory to move the tomb from its previous location.
The tomb complex, which is considered sovereign Turkish territory, had been located some 37 kilometres (23 miles) inside Syrian territory.
But the government ordered the tomb, which has a permanent honour guard of Turkish troops, to be moved due to security concerns as it was located in territory controlled by Islamic State (IS) jihadists.
Army chief of staff Necdet Ozel, flanked by commanders from land and air forces, visited the tomb in March.
The tomb of Suleyman Shah, who is said to have died in 1236, is considered Turkish territory under the 1921 Treaty of Ankara between the Turkish authorities and France, which then controlled French-mandated Syria.
The latest visit comes amid speculation that Turkey is preparing to intervene militarily in Syria, a claim rejected by Davutoglu.
Some politicians in the opposition Republican People's Party (CHP) claimed this week that the ruling Justice and Development Party (AKP) might resort to military operations in Syria to boost its popularity ahead of a June 7 parliamentary election.
"No, there is no situation right now that requires Turkey's involvement," Davutoglu told Turkish media this weekend, labelling the claims as "empty words".
Davutoglu was due to continue his election rally on Sunday in the city of Sanliurfa in the southeast near the Syrian border.