There are no known casualties among U.S. personnel assigned to Incirlik Air Base in Turkey, and no major damage to facilities, a base spokesperson told ABC News.

The base is roughly 125 miles from the earthquake's epicenter.

The 39th Air Base Wing at Incirlik "is still mission operational," the spokesperson said in a statement.

The Air Force is prepared to assist Turkey if called upon, according to the spokesperson.

-ABC News’ Matt Seyler

More than 2,800 buildings across Turkey have been completely destroyed, according to Turkey’s Emergency Management Agency, while over 1,400 buildings were demolished in Syria, according the Syrian Civil Defense Agency.

At least 45 nations have pledged to send volunteers and other aid to Turkey, Turkish President Recep Tayyip Erdogan said.

President Joe Biden tweeted that he’s “deeply saddened by the loss of life and devastation” from the earthquake.

“I have directed my team to continue to closely monitor the situation in coordination with Turkiye and provide any and all needed assistance," he tweeted.

The United Kingdom announced Monday it is “immediately” deploying emergency response teams to Turkey to assist rescue efforts following a deadly earthquake and powerful aftershocks.

According to a press release from the U.K. Foreign, Commonwealth and Development Office, 76 U.K. search and rescue specialists, four search dogs as well as rescue equipment will arrive in Turkey on Monday evening. A U.K. emergency medical team is also being sent to assess the situation on the ground.

“We stand ready to provide further support as needed,” U.K. Foreign Secretary James Cleverly said in a statement.

In northwestern Syria, where the quake was also felt, the U.K.-aid funded volunteer organization White Helmets has activated a significant search and rescue response and mobilized all its resources to respond to emerging needs. The U.K. government is in contact with the United Nations on emergency humanitarian support to those affected in Syria, according to the U.K. Foreign, Commonwealth and Development Office.

“The British Embassy in Ankara is in close contact with the Turkish authorities to understand how we can best support those on the ground,” Jill Morris, British Ambassador-Designate to Türkiye said in a statement. “Our thoughts are with all those affected by the earthquakes today We pay tribute to the brave Turkish first responders working to save lives.”

The U.K. government’s announcement came on the heels of the Turkish Disaster and Emergency Management Authority (AFAD) declaring a “level 4 alarm” in the wake of the pre-dawn earthquake, calling for international assistance.

More than 24 hours after devastating earthquakes, ABC News reporters on the ground are witnessing the fevered effort to rescue survivors at a collapsed apartment building in southeastern Turkish city of Diyarbakir.

ABC News learned that crews had recently rescued a woman from what used to be an eight-story apartment building, where the top half now rests on three flattened floors below. The front wall had fallen away, exposing what used to be homes with furniture, pillows and air conditioning units.

In and around the collapsed building, there was a flurry of activity -- but then a moment when it all came to a grinding halt. Generators were turned off, everyone stopped talking and the block went silent. Search and rescue teams thought they may have found another survivor. It was quiet for several minutes, but then the urgent effort returns.

Rescuers continued working in the cold, wet weather while also facing the threat of aftershocks. None of that has deterred them. They know this is a race against time.

-ABC News’ Engin Bas, Ibtissem Guenfoud and Marcus Moore