IHA agency via AP A powerful 7.8 magnitude earthquake hit southern Turkey and northern Syria early Monday, toppling buildings and killing at least 641 people.

"I don't have the strength anymore," one survivor could be heard calling out from beneath the rubble as rescue workers tried to reach him, said the resident, journalism student Muhammet Fatih Yavus.

On the Syrian side of the border, the quake smashed opposition-held regions that are packed with some 4 million people displaced from other parts of Syria by the country's long civil war.

U.S. National Security Adviser Jake Sullivan issued a statement saying, "The United States is profoundly concerned by the reports of today's destructive earthquake in Turkiye and Syria.

Turkey's defense ministry said Turkish armed forces set an air corridor to enable search and rescue teams to get to the quake zone, according to Reuters.

In northwest Syria, the opposition's Syrian Civil Defense described the situation in the rebel-held region as "disastrous" adding that entire buildings have collapsed and people are trapped under the rubble.