U.N. Under-Secretary-General for Humanitarian Affairs and Emergency Relief Coordinator Martin Griffiths is in Türkiye and will travel to Syria on the weekend to analyze the needs and how the U.N. can ramp up support amid the ongoing humanitarian tragedy following two devastating earthquakes in the region, according to Secretary-General Antonio Guterres.

Griffiths will visit Gaziantep in Türkiye and Aleppo and Damascus in Syria.

Guterres also pushed for more aid access to opposition-controlled northwest Syria.

"Roads are damaged. People are dying. Now is the time to explore all possible avenues to get aid and personnel into all affected areas. We must put people first," Guterres told reporters in New York.

The U.N. chief said Wednesday the United Nations would issue a flash appeal early next week to support humanitarian needs in Türkiye following the country's deadly earthquakes.

''We will be issuing early next week a flash appeal," Antonio Guterres told Anadolu after signing a book of condolence at the Turkish House in New York for the victims of the devastating quakes.

Guterres paid a visit to the Turkish Ambassador to the U.N., Feridun Sinirlioğlu, to convey his condolences to the people of the earthquake-hit country.

He said he sent the U.N. emergency relief chief to Türkiye to assess the needs.

''Martin Griffiths is in Gaziantep. He will also go to Aleppo, and we are doing everything to mobilize the U.N. system,'' Guterres said.

''Naturally, in Türkiye, we have a solid capacity, even if this disaster is tremendous. In Syria, for instance, we still are in a war situation. But our solidarity with the people of Türkiye is total.''

He said he witnessed the enormous generosity and solidarity of the Turkish people for the millions of Syrian refugees when he served as the U.N. high commissioner for refugees.

''This generous population now deserves the same kind of solidarity, the same kind of commitments by the whole international community,'' Guterres said.

According to Turkish authorities, the death toll in Türkiye from Monday's massive earthquakes has risen to 16,546, with more than 66,000 injured.

Other provinces in southern Türkiye that were affected by the quakes are Gaziantep, Hatay, Osmaniye, Adıyaman, Malatya, Şanlıurfa, Adana, Diyarbakır and Kilis.