UNITED NATIONS (AP) — The United Nations launched a $1 billion appeal Thursday to help 5.2 million survivors of the most devastating earthquake in Turkey’s modern history, two days after starting a $397 million appeal to help nearly five million Syrians across the border in the rebel-held northwest.

UN spokesman Stephane Dujarric was peppered with questions about why the appeal for Turkey is targeted at only 5.2 million people when according to the UN and the government more than 15 million people were affected. He also was asked why the appeal for Turkey is 2½ times larger than the one for Syria to help almost the same number of people.

He said the Turkish appeal “was designed in very close cooperation with the government of Turkey, which is leading the relief efforts.”

“This is the number they came up with for the focus on people who need the most humanitarian aid, most quickly, and where the UN can be most effective,” Dujarric said. He said Turkey has “a very efficient search and rescue and humanitarian system.”

As for the disparity in the amount of the appeals, he said, part of the reason is that “there is already a well-established humanitarian community which has been working in Syria,” and before the quake there was a $4.8 billion humanitarian appeal for Syria for 2023.

“So there’s already a humanitarian pot of money that exists for Syria, which did not exist for Turkey,” he said.

Both appeals are for emergency funds for the next three months, and will be followed by fresh appeals for longer-term help.

UN Secretary-General Antonio Guterres announced the $1 billion appeal for Turkey saying the money will allow aid groups to rapidly scale up support for government-led relief efforts, including providing food, protection, education, water and shelter to survivors of the magnitude 7.8 quake on February 6 that devastated southern Turkey and northwestern Syria.

“The needs are enormous, people are suffering and there’s no time to lose,” Guterres said. “I urge the international community to step up and fully fund this critical effort in response to one of the biggest natural disasters of our times.”

He said that “Turkey is home to the largest number of refugees in the world and has shown enormous generosity to its Syrian neighbours for years,” so it is time for the world to support the Turkish people.

More than 1.74 million refugees live in the 11 Turkish provinces affected by the earthquakes, according to the UN refugee agency.

UN humanitarian chief Martin Griffiths, who visited both quake-ravaged countries last week, said: “The people of Turkey have experienced unspeakable heartache.”

The earthquake struck at the peak of winter, leaving hundreds of thousands of people, including small children and the elderly, without access to shelter, food, water, heaters and medical care in freezing temperatures. Griffiths’ office said some 47,000 buildings have been destroyed or damaged.

“We must stand with them in their darkest hour and ensure they receive the support they need,” Griffiths said.

The United Nations has been criticised for the slow response in getting aid and heavy equipment into Syria’s rebel-held northwest since the earthquake struck 10 days ago.