The number of deaths that have been officially recorded in the two countries has risen above 4,300, following a massive quake at the Turkey-Syria border .
The death toll reached 2,921 in Turkey alone, bringing the confirmed tally of death to 4,365, country's relief agency AFAD said on Tuesday.
More than 5,600 buildings have been flattened across several cities, including many multi-storied apartment blocks.
With WHO officials estimating up to 20,000 deaths, there are fears that toll will rise exponentially.
Dozens of nations from Ukraine to New Zealand have vowed to send help, although freezing rain and sub-zero temperatures have slowed the response.
A massive 7.8-magnitude quake struck at 4:17am (0117 GMT) near the Turkish city of Gaziante, which was followed by a series of aftershocks, the biggest recorded worldwide by the US Geological Survey since a tremor in the remote South Atlantic in August 2021.