At least 22 American citizens have died as a result of unfolding violence in Israel, the State Department confirmed Wednesday as the death toll continues to rise.

The number represents an increase from just a day earlier, when President Biden said 14 Americans were among those killed.

White House press secretary Karine Jean-Pierre told reporters there are 17 Americans who are still unaccounted for.

“We know these numbers are likely to increase in the days ahead,” she said.

More than 1,000 Israelis have died since Hamas, the militant group that controls Gaza, launched attacks against Israel on Saturday. Hundreds of Palestinians have died in ensuing fighting in Gaza.

The White House has also confirmed that U.S. citizens are among those being held hostage by Hamas following the wide-scale attacks, which President Biden on Tuesday called “terrorism” and “an atrocity on an appalling scale.”

The exact number of Americans being held by Hamas is unclear. In addition to military resources, the Biden administration has dispatched experts to assist with hostage negotiations.

Biden spoke Wednesday with Israeli Prime Minister Benjamin Netanyahu, and he has repeatedly said the United States will offer unwavering support to Israel in the aftermath of the attacks.

“We continue to monitor the situation in Israel very closely,” Biden said at the start of an event on eliminating so-called junk fees. “My commitment to Israel’s security and the safety of the Jewish people is unshakable. The United States has Israel’s back.”

Biden later Wednesday is scheduled to speak at a roundtable discussion at the White House involving Jewish leaders and members of his national security team.

— Updated at 1:39 p.m.