Turkey’s president on Wednesday fired back at the United Nations for demanding that Turkey open its border to tens of thousands of more Syrian refugees, accusing the world body of being ineffective over the refugee crisis and of not shouldering the burden like Turkey.

The war in Syria against President Bashar Assad’s government has killed more than 250,000 people and forced millions to flee their homes since it began in 2011. More recently, a Russian-backed Syrian government offensive around Aleppo has sent tens of thousands of people fleeing to the Turkish border in recent days.

Turkey, already home to about 3 million refugees — 2.5 million of them Syrians — is providing assistance to the new wave of refugees at displaced persons camps on the Syrian side of the border. It has kept a key border crossing for refugees closed, prompting UNHCR on Tuesday to call on Turkey to admit “all civilians who are fleeing danger and seeking international protection as they have done since the start of this crisis.”

Prime Minister Recep Tayyip Erdogan responded to that demand by saying the U.N. had provided $455 million to Turkey compared to the $10 billion Turkey had spent on the refugees since 2011.

“What does the U.N. say? ‘Open your border to the refugees.’ What are you for then? What is your use? Is it that easy?” Erdogan asked. “We have taken 3 million Syrians and Iraqis into our home until now. How many did you take? Which country took them in?”

On Wednesday, Suleyman Tapsiz, the governor for the border province of Kilis, said Turkey allowed in 12 Syrians who were seriously injured in Russian and Syrian bombings near the town of Tel Rifaat, in northern Syria. One of them has since died while the others were in stable condition, he told NTV television in an interview.

The governor denied accusations that Turkey had closed its borders to the refugees, insisting that the country had chosen to assist the new arrivals at the displaced peoples’ camps just across the border, but would let them in if the need arises later.

“Our doors are not shut,” Tapsiz said. “There is no need to take them in because all of their needs are being taken care of.”

Tapsiz said, however, that Turkey had made all preparations in case it becomes necessary to take them in, including preparing camps and deploying mobile units to process the refugees.

Tapsiz acknowledged that conditions on the other side of the border were “difficult,” but said the camps were constantly being improved and new ones were under construction.

Doctors Without Borders said Tuesday that about 23,000 new arrivals fleeing the fighting in Aleppo were in urgent need of emergency shelter and support near Syria’s border with Turkey.

The group said it had increased the number of beds in its hospital in Azaz district to 36 beds from 28 and is preparing to extend capacity if necessary. The group says it has distributed hundreds of blankets, tents, mattresses and other supplies.

Meanwhile, Turkey’s state-run agency Anadolu Agency said military officials have detained a group of 34 people at the border with Syria and seized luggage containing four suicide vests and explosives. Citing unnamed security sources, Anadolu said four men, 10 women and 20 children were stopped near the town of Oguzeli, in Gaziantep province. Anadolu said that security forces had acted on a tip about plans to smuggle explosives across the border.

The luggage contained up to 15 kilograms (33 pounds) of explosives. The report didn’t say whether authorities believe the group may be linked to the Islamic State group.