Turkey is determined to push on with its massive offensive against Kurdish forces in Syria, President Recep Tayyip Erdogan said on Monday, as Turkish forces encountered heavy resistance on the third day of its invasion on the city of Afrin.

"There is no stepping back from Afrin," Erdogan said.

Turkey launched the ground assault to drive Kurdish forces away from its southern borders and prevent the creation of Kurdish-dominated statelet which could further destabilize Kurdish-populated areas in Turkey.

According to Britain-based Syrian Observatory for Human Rights, Syrian Kurds launched an intense counterattack on Sunday evening, pushing Turkish troops and their allies out of two villages they briefly captured.

The watchdog said that at least 26 SDF fighters and 19 pro-Turkish rebels were killed in the three days of fighting, with nine unidentified bodies also found on the battlefield. Another 24 civilians were reportedly killed.

Speaking in Ankara on Monday, Erdogan said Turkey's "fundamental goal" was ensuring national security, preserving Syria's territorial integrity, and protecting the Syrian people. He added that the goal was not to occupy parts of Syria, but to win over "hearts" of the population.

SDF says Afrin will be a Turkish 'quagmire'

Also on Monday, the Kurdish-dominated Syrian Democratic Forces (SDF) said Ankara's attack amounted to "clear support" to the "Islamic State" (IS) terror militia. The Syrian SDF force is largely made-up of Kurdish YPG units, which Turkey considers to be a terrorist organization.

The SDF is also heavily backed by the US. The US provided the group with training, arms, and equipment in the war against the "Islamic State." With the help of American special forces and air power, the SDF led the battle to drive the jihadists out of their de-facto capital of Raqqa three months ago.

Read more: US tells Turkey to show 'restraint' with Syria Kurds

"The international coalition, our partner in the fight against terrorism with whom we jointly conducted honorable battles... knows full well this Turkish intervention comes to make final victory hollow," the SDF said in a statement.

"For this reason, the coalition is urged to take its responsibilities towards our forces and our people in Afrin," the group's spokesman, Keno Gabriel, said.

The group also pledged that the northwestern city of Afrin would become a "quagmire from which the Turkish army will only exit after suffering great losses."

Kurdish leaders also blamed Moscow for allowing Turkish planes to fly over Syrian territory and pulling out Russian troops stationed in Afrin. According to YPG officials, Russia urged them to hand over the Afrin enclave to avoid the Turkish attack. This was apparently corroborated by Erdogan on Monday, who said Turkish officials discussed the invasion "with our Russian friends and we have an agreement."

UN stays on sidelines

Despite calls for restraint from the international community, the United Nations Security Council neither condemned or demanded an end to the Turkish operation, during a meeting on Monday about the issue and the worsening humanitarian crisis in Syria.

Germany's Foreign Minister Sigmar Gabriel telephoned his Turkish colleague Mevlut Cavusoglu to relay his "concerns about an escalation" in northern Syria on Monday, as well as the impact on the civilian population, according to a foreign ministry official in Berlin.

Read more: Germany, Turkey and the 2017 diplomatic rollercoaster

The co-chair of Germany's Left Party, Katja Kipping, released a video statement on Twitter in which, wearing a scarf in the colors of the Kurdish flag, she accused Russia and NATO of betraying the Kurds and making Germany complicit in a "war of aggression."

She said Russia had opened Syrian airspace for Turkish warplanes and that NATO had approved the move, while, according to the Turkish military, NATO reconnaissance aircraft were coordinating and observing the Turkish operations.

"If what the Turkish general staff has announced is true, it means German soldiers are also directly involved in this war of aggression," Kipping said. 

EU foreign policy chief Federica Mogherini said she was "extremely worried" over the Turkish incursion into Syria, adding that she would raise the issue with Ankara.

The attack "can undermine seriously the resumption of talks in Geneva, which is what we believe could really bring sustainable peace and security for Syria," she said, a reference to the UN peace effort.

German-made tanks move towards Afrin

Read more: Turkish jets bomb Syria's Afrin

Turkey's push into Syrian territory also sparked uproar in Germany as photos from the scene purported to show Turkish troops using German-made Leopard 2 tanks. Opposition lawmakers slammed the German government for exporting weapons to Turkey and called for the deliveries to be halted.

German officials refused to provide details on the apparent Leopard deployment. A defense ministry spokesman said that it was not yet clear when the pictures were taken, while foreign ministry officials said the situation remained unclear. A spokesman dealing with weapons exports in the economy ministry was equally tight-lipped.

"Except for the images shown in the media, which you all know about, we do not have any information about the use of Leopard tanks."

dj, tj/msh (AFP, dpa, AP, Reuters)