More than 20,000 people are now known to have been killed in Monday’s earthquakes in Turkey and Syria, though the UN warns the disaster’s full extent is still unclear.
Rescuers are still searching rubble for survivors, but hopes are fading more than four days since the first quake.
Freezing conditions threaten the lives of thousands of survivors who are now without shelter, water and food.
Turkey’s president called the quake “the disaster of the century”.
A major international relief effort is gathering pace. On Thursday the World Bank pledged $1.78bn in aid to Turkey including immediate finance for rebuilding basic infrastructure and to support those affected by the earthquakes.
But the efforts of 100,000 or more rescue personnel on the ground are being hampered by a number of logistical hurdles including vehicle shortages and devastated roads.
UN chief Antonio Guterres warned the full extent of the catastrophe was still “unfolding before our eyes”, especially in Syria where a long-running civil war has devastated the country.
On Thursday, the first UN humanitarian aid crossed the border into north-western Syria through Idlib’s Bab al-Hawa crossing. The crossing is the only way UN aid can reach the region without travelling through areas controlled by Syrian government forces.