In the wake of brutal and ongoing attacks in Israel by the militant group Hamas -- which have already led to the deaths of hundreds -- Secretary of State Antony Blinken on Sunday said that the U.S. had pledged its "full support" to the Israeli government and engaged allies in the region to ensure they are doing everything possible to repel the attackers and prevent the violence from spilling into other parts of the Middle East.
"This is a massive terrorist attack that is gunning down Israeli civilians in their towns, in their homes, and as we've seen, so graphically, literally dragging people across the border with Gaza, including a Holocaust survivor in a wheelchair, women and children," the secretary told "This Week" anchor George Stephanopoulos.
"The world should be revolted at what it's seen," he said.
Early Saturday, fighters from Hamas -- a group designated as a terrorist organization by the U.S., Israel and the European Union and which controls Gaza, the Palestinian territory adjacent to Israel -- launched a surprise large-scale assault in southern Israel, indiscriminately attacking soldiers and civilians, according to officials.
On Sunday, fighting continued at multiple flashpoints as the Israel Defense Forces (IDF) sought to regain control of several sites. Israel had launched numerous retaliatory strikes as well.
Blinken said on "This Week" that of the approximately 1,000 Hamas militants that infiltrated Israel, most had since been killed or retreated into Gaza but that "intense fighting remains."
So far, Israeli health officials say more than 600 people have been killed in Israel and more than 2,100 have been injured. The Israeli government said Sunday that at least one hundred individuals were also still being held hostage by militants.
More than 370 people in Gaza have been killed and at least 1,700 have been wounded in the strikes carried out by Israel, according to the Palestinian Health Ministry.
MORE: Hamas attacks in Israel: Airlines that have suspended flights amid travel advisoryBlinken said in other Sunday show appearances that the State Department was "working overtime" to verify reports of Americans killed or held hostage in the Hamas onslaught.
Tensions between Israelis and Palestinians have been heightened for months, but Hamas' attack -- unprecedented in both its scale and sophistication -- appears to have blindsided Israel, suggesting a massive intelligence failure.
"There'll be time to look at that and to make determinations about what may have been missed," Blinken said when pressed on the matter by Stephanopoulos. "Right now, the focus has to be on the effort to repel the aggression by the Hamas terrorists, to push them back and to put Israel in a position where this doesn't happen again."
Israel's security cabinet voted to officially declare war over the weekend for the first time since 1973, nearly 50 years to the day since the start of the Yom Kippur War -- a weekslong conflict against a coalition of Arab states where U.S. support for Israel was a decisive factor in the country's victory.
In response to this weekend's expansive attack, Israeli Prime Minister Benjamin Netanyahu has vowed to "destroy Hamas" and signaled that the country's forces will soon go on the offensive as the IDF evacuates civilians living near the border with Gaza.
Blinken said Sunday that the U.S. would stand behind Israel as it did whatever necessary to ensure "this doesn't repeat itself."
"I don't want to get ahead of what Israel may or may not do when it comes to Gaza," he said when asked whether Israel could control the situation if it invaded. "No country should be expected to live with the fear, the possibility and now the actuality of terrorists crossing a border, coming into people's homes, gunning them down in the street, dragging them across the border and making hostages of them. That is intolerable for any democracy. It's intolerable for Israel."
Republicans have criticized the Biden administration approach toward Iran, Hamas' largest sponsor, contending that the White House in effect enabled the attack and emboldened the extremists by facilitating Iran's access to sanctioned finances for humanitarian expenditures as part of a separate deal to free American detainees.
House Majority Leader Steve Scalise said in a statement that the money transfer was a sign of "appeasement." Other critics said it would free up Iran to better financially support Hamas.
MORE: Attack on Israel shows 'irresponsibility' of Republicans paralyzing House: ChristieBlinken, on "This Week," pushed back.
"There's a long relationship between Iran and Hamas. In fact, Hamas wouldn't be Hamas without the support that it's gotten over many years from Iran. We haven't yet seen direct evidence that Iran was behind this particular attack or involved," he said.
"It's unfortunate that some are, in effect, saying things that may be motivated by politics at a time when so many lives have been lost and Israel remains under attack," he continued, noting the funds are held in a restricted account monitored by the U.S. Treasury Department.
"By the way, not a single dollar from that account has actually been spent to date," Blinken asserted, adding, "So, some who are advancing this false narrative -- they're either misinformed or they're misinforming. And either way, it's wrong."