Turkey and the Syrian National Army have launched their much-awaited operation against Daesh and the People's Protection Units (YPG) terror groups in northern Syria, President Recep Tayyip Erdoğan announced Wednesday.

"Our aim is to destroy the terror corridor, which is trying to be established on our southern border, and bring peace to the region," Erdoğan wrote on Twitter.

The operation, dubbed "Peace Spring," will eliminate the terrorist threat to Turkey and ensure Syrian refugees' return to their country thanks to a safe zone in the area, he said.

"We will protect the territorial integrity of Syria, and free the people of the region from the clutches of terror," the president added.

By Wednesday evening, Turkish fighter jets had struck targets of the People's Protection Units (YPG) terror group 30 kilometers deep into Syria, according to the official Anadolu Agency. Turkish forces reportedly advanced up to 25 kilometers near Tal Abyad and Ras al-Ayn, destroying YPG ammunition.

Once darkness had fallen on Wednesday night, Turkish ground troops crossed the border and entered northeastern Syria, the Defense Ministry said.

Turkish jets shelled 181 posts belonging to terrorist organizations in northeast Syria in the first hours of Operation Peace Spring, the ministry said late Wednesday.

The Defense Ministry said the Turkish forces are taking great care not to harm civilians and allied troops in the area.

The ministry also said Turkish operation in northeastern Syria is only targeting terrorists and their bases, weapons and tools.

Meanwhile, the Turkish Foreign Ministry summoned U.S. Ambassador to Ankara David Satterfield to be briefed on Operation Peace Spring.

The ministry also summoned ambassadors of other U.N. Security Council members for a briefing. Diplomats said Wednesday that the Security Council will meet Thursday to discuss Syria at the request of its European members.

Erdoğan also informed the main opposition Republican People's Party (CHP) Chairman Kemal Kılıçdaroğlu, the Justice and Development Party (AK Party)'s People's Alliance partner the National Movement Party (MHP) Chairman Devlet Bahçeli and the opposition Good Party (IP) Chairman Meral Akşener about the Syria operation.

Foreign Minister Mevlüt Çavuşoğlu said Wednesday that Ankara informed the Assad regime about the operation with a diplomatic note delivered to Istanbul consulate.

Earlier this week, the United States pulled its forces from the areas targeted by the Turkish operation.

Later on Wednesday Foreign Minister Çavuşoğlu held a phone call with his U.S. counterpart Mike Pompeo.

Most of northeastern Syria is controlled by the U.S.-backed Syrian Democratic Forces (SDF), which is dominated by YPG terrorists. The YPG is the armed wing of the Democratic Union Party (PYD), the PKK terror group's Syrian affiliate.

The PKK — listed as a terrorist organization by Turkey, the U.S. and the European Union — has waged a terror campaign against Turkey for more than 30 years, resulting in the deaths of nearly 40,000 people, including women, children and infants.

Turkey has long decried the threat from terrorists east of the Euphrates in northern Syria, pledging military action to prevent the formation of a "terrorist corridor" there.

Since 2016, Turkey's Euphrates Shield and Olive Branch operations in northwestern Syria have liberated the region from YPG/PKK and Daesh terrorists, making it possible for nearly 400,000 Syrians who fled the violence to return home.