Erdogan defiant as Syrian troops approach Turkish border

Turkish President Recep Tayyip Erdogan has attacked Russia's intervention in the Syrian war, as Syrian regime troops advance towards rebel-held territories on the country's southern border, backed by Moscow's air force.

Erdogan accused Moscow of being an "occupation force" and involved in "state terrorism", as a massive aerial bombardment by Russian planes in northern Syrian helped regime troops capture key rebel positions in Aleppo.

Damascus' victory led to a civilian exodus as tens of thousands attempt to cross the border into Turkey.

"If needed, we will let those brothers in," Erdogan was quoted as saying.

Aid agencies on the Turkish side of the border were on Sunday preparing to deliver further aid across the frontier, where relief shelters have been set up.

"We're extending our efforts inside Syria to supply shelter, food and medical assistance to people. We are already setting up another camp," an official from the Turkish Humanitarian Relief Foundation told Reuters. 

Tensions

Anakara's relations with Moscow have been strained after Turkey shot down a Russian war plane which strayed into its territory.

Tensions have been ongoing during the five-year Syrian war due to Turkey's support for Syrian rebels, while Russia backs President Bashar al-Assad's regime.

"The Russians claim that we are preparing a military action in Syria, I would like to ask the Russians, what are you doing in Syria?" Erdogan rhetorically asked Russia in a press conference on Sunday. 

"You are an occupation force and you are practicing a state terrorism. You are cooperating with someone who killed over 400,000 people and you continue the killing of civilians."

Rebel retreat

Turkey shares a long and porous border with Syria, but recently closed the border despite tens thousands of civilians being stranded on the border.

They were made homeless after regime forces captured a key road controlled by the rebels, connecting Aleppo with Turkey.

Now regime troops are poised to completely encircle opposition-held Aleppo and are advancing on a rebel-held town close to Syria's northern border.

Erdogan said Turkey would do what is necessary "to protect themselves", amid growing speculation Ankara might carve out a safe zone for refugees in the north of Syria.

Despite the regime's advances in the north, dozens of troops were killed in clashes in the Damascus suburbs.

Jaish al-Islam said its fighters killed 50 government soldiers when the regime launched an offensive in Eastern Ghouta to cut off the rebel group's stronghold in Douma.

During the press conference, Erdogan also appeared to voice his support for a solution to Washington's use of an air base in southern Turkey.

The Turkish President added that he would refuse to meet Egyptian President Abdel Fattah al-Sisi even if the death sentence was lifted on the country's first democratically elected leader Mohamad Morsi.