File Photo: Turkish President President Tayyip Erdogan Photograph:( Reuters )
'We will not allow the regime's cruelty towards its own people, with attacks and causing bloodshed,' Erdogan said.
"We will not allow the regime's cruelty towards its own people, with attacks and causing bloodshed," Erdogan said.
Syria was also "continuously threatening our country with migration," he said during a speech in Ankara.
"Turkey with complete sincerity wants Syria's stability and security, and to this end, we will not shy away from doing whatever is necessary including using military force."
He also said Turkey "could not stand by as mere spectators as new threats come towards our borders".
Hundreds of thousands of Syrians have been displaced in Idlib since December after months of bombardment in the last rebel-held region in Syria's northwest.
Many of them have fled towards the Turkey-Syria border, where Erdogan has said Ankara is building homes in a bid to prevent further migration.
Turkey already shelters more than 3.5 million Syrians.
Watch: 80,000 Syrian migrants marching to Turkey, says Recep Erdogan
State news agency Anadolu reported Wednesday that the Turkish army sent reinforcements to Reyhanli, a Turkish border town near Idlib.
Erdogan said the only solution for Syria was a political process involving all citizens.
He hit out at unnamed countries who "give courage to the regime" in a bid to ensure the crisis continues.
Earlier this week, Erdogan offered rare criticism of Russia, accusing Moscow of "not honouring" agreements made with Ankara to prevent a regime offensive on Idlib.
Despite Russia assisting Syrian President Bashar al-Assad and Turkey supporting opposition fighters, Ankara and Moscow have worked closely to try to resolve the nine-year war.
Ten civilians were reportedly killed Thursday by Russian airstrikes despite a ceasefire announcement, though Moscow denied it.
Turkey has previously launched three military operations against the Islamic State extremist group in Syria and a Syrian Kurdish militia in 2016, 2018 and 2019.