U.S. Defense Secretary Lloyd Austin spoke with Israeli Minister of Defense Yoav Gallant by phone on Sunday to express his condolences for the IDF soldiers killed in a Hezbollah drone attack and discuss the IDF's military operations in Lebanon.

According to a readout of the call from the Pentagon, Austin, "reinforced the importance of Israel taking all necessary measures to ensure the safety and security of UNIFIL forces and Lebanese Armed Forces, and the need to pivot from military operations in Lebanon to a diplomatic pathway to provide security for civilians on both sides of the border as soon as feasible."

The United Nations Interim Force in Lebanon (UNIFIL) is a peacekeeping mission in Lebanon established by the U.N. Security Council.

The conversation comes after the IDF has repeatedly fired on the UNIFIL headquarters in southern Lebanon.

Additionally, Secretary Austin "reaffirmed the deep U.S. commitment to Israel’s security," which he says is demonstrated by the deployment of the U.S. Terminal High Altitude Area Defense (THAAD).

According to the Department of Defense, THAAD employs interceptor missiles, using “hit-to-kill” technology, to destroy threat missiles.

During the call, Austin "again raised concern for the dire humanitarian situation in Gaza and stressed that steps must be taken soon to address it," the Pentagon said.

At least three people were killed and dozens more were injured after Israel Defense Forces struck Al Aqsa Hospital in Gaza on Sunday.

-ABC News' Will Gretsky

The Israel Defense Forces said Hezbollah struck one of its bases Sunday, killing at least four soldiers.

Another seven soldiers were "severely injured," according to the IDF statement.

"The IDF shares in the grief of the bereaved families and will continue to accompany them," the IDF said.

At least 22 people were killed after the Israel Defense Forces shelled a school housing displaced people in the Al-Mufti area, north of Nuseirat, in the central Gaza Strip, the Gaza Health Ministry said Sunday.

Among the deceased were 15 women and children, officials said, and at least 80 others were injured.

-ABC News' Will Gretsky

President Joe Biden and first lady Jill Biden joined a memorial candle lighting held Monday in the Blue Room of the White House in remembrance of the victims of the Oct. 7 attack.

Rabbi Aaron Alexander recited in Hebrew "El Malei Rachamim" ("God Full of Mercy"), a traditional Jewish prayer for those who have died, then recited it in English.

Biden then lit the yahrzeit candle before observing a moment of silence. Biden made the sign of the cross after a few moments.

Alexander is a family friend of the Goldberg-Polin family. American-Israeli Hersh Goldberg-Polin, 23, was taken hostage by Hamas on Oct. 7 at the Nova Music Festival. His body was recovered by Israeli forces in late August.

Biden also spoke with Israeli President Isaac Herzog earlier Monday to express his "deepest condolences" to Israelis and families of the Oct. 7 attack, the White House said.

-ABC News' Justin Ryan Gomez