Israel-Gaza updates: Netanyahu says Israel 'can't be flexible' on some issues

The U.S. State Department has signed off on several large arms transfers to Israel, notifying Congress on Tuesday that it has approved the sale of more than $20 billion worth of weaponry and military equipment.

All of the sales surpass the value threshold that requires the State Department to formally notify Congress 15 days before initiating the transfer process. Congress can move to reject the transaction by adopting a joint resolution of disapproval within that timeframe.

Some of the items aren’t scheduled to arrive in Israel for years.

-ABC News' Shannon K. Kingston

Israeli forces killed two Hezbollah fighters from its Southern Front on Tuesday, the Israeli Defense Forces said in a statement. Hezbollah has confirmed the death of two of their fighters on Tuesday.

These attacks come as Israel awaits a response from Hezbollah and Iran for killings in recent weeks.

Several U.S. officials are headed to the Middle East this week in a bid to de-escalate regional tensions and try to salvage hostage negotiations, as the window for a deal appears to be closing.

CIA Director Bill Burns is expected to arrive in Doha, Qatar, this week, where he will lead a crucial meeting on the hostages, according to a U.S. official. It’s not clear, however, whether a representative of Hamas will attend.

Meanwhile, Brett McGurk, Biden’s top adviser on the Middle East at the White House, was expected to travel separately to Cairo, according to the U.S. official.

Axios first reported the travel plans for Burns and McGurk, noting that McGurk’s plan was to nail down a security plan for the Egypt-Gaza border.

The diplomatic trip also comes as the U.S. has been scrambling to revive a coalition of countries that helped to defend Israel last April during an attack by Iran.

Israel has been bracing for Iran to launch a retaliatory attack following the assassination of a senior Hamas official in Tehran.

The U.S. official acknowledged "there have been complications" with getting some of the Arab countries on board but added they've been "able to put in place preparations" to defend Israel successfully.

-ABC News' Anne Flaherty

The leaders of the U.S., U.K., France, Germany and Italy called on Iran to "stand down" and expressed their support for Israel's defense "against Iranian aggression" during a call on Monday, according to a joint statement released by the White House.

“We called on Iran to stand down its ongoing threats of a military attack against Israel and discussed the serious consequences for regional security should such an attack take place," the statement said.

The leaders also expressed their support for ongoing efforts to reach a cease-fire and hostage release deal in Gaza, according to the statement.

-ABC News' Justin Gomez