The death toll from the Turkey-Syria earthquake has surpassed 15,000

According to Turkish officials, nearly 12,000 people perished in Turkey alone as a result of the earthquake.

The death toll from earlier this week's earthquakes in Turkey and Syria increased to more than 15,800 on Thursday as rescuers searched for survivors trapped beneath the wreckage in frigid winter temperatures.

According to the Turkish national news agency Anadolu Agency, which cited the country's disaster management department, the quake killed 12,873 people in Turkey alone.

Meanwhile, Syria's health ministry has estimated that over 1,200 people have died in government-controlled parts of Syria. At least 1,600 people were killed, according to the White Helmets response organization located in Syria's rebel-held northwest.

On Wednesday, the Turkish government conceded that the country's catastrophe response should have been better.

Access to Twitter in the nation, which had been restricted following a barrage of online criticism of authorities, was restored early Thursday following negotiations between the firm and Turkish officials.

A destroyed apartment and damaged vehicle in Yurt neighborhood of Cukurova district after the earthquake in Adana, Turkey. Credit: Omer Yildiz/Anadolu Agency/Getty Images

Summary of Wednesday's earthquake events in Turkey and Syria

Turkey's Foreign Minister, Mevlut Cavusoglu, said his country is seeking to open two more border crossings into Syria to allow humanitarian supplies into the war-torn country.

In the aftermath of Monday's terrible earthquake, European Commission President Ursula von der Leyen announced a donor conference for international relief to Syria and Turkey in March.

For the first time in 24 years, the Istanbul stock market declared a five-day shutdown in reaction to the earthquake.

Turkish President Recep Tayyip Erdogan admitted "shortcomings" in his country's reaction to the massive earthquake during a visit to the disaster area.

According to the EU's commissioner for crisis management, the sanctions-hit Syrian government has made an official request for emergency assistance through the civil protection mechanism.