As Israeli forces pushed deeper into Rafah just days after an airstrike sparked a major fire that killed dozens of Palestinians, the White House said that its ally had not crossed the Biden administration’s “red line.”

Israeli tanks were seen entering central Rafah for the first time Tuesday, as global condemnation mounted over the deaths in a crowded tent camp for displaced civilians and as U.S. aid deliveries to Gaza by sea were suspended after damage to its temporary pier.

But National Security Council spokesman John Kirby told reporters at a briefing that the United States was not turning a “blind eye” to Israel’s operations in the southern Gaza city, from which around 1 million Palestinians have fled in recent weeks.

He said the Biden administration did not believe Israel’s actions in Rafah so far represented a “major ground operation” that would violate President Joe Biden’s warnings and trigger a change in U.S. policy including the threatened halt to weapons shipments.

Biden told CNN earlier this month: “I made it clear that if they go into Rafah — they haven’t gone in Rafah yet — if they go into Rafah, I’m not supplying the weapons that have been used historically to deal with Rafah, to deal with the cities — that deal with that problem.”

Asked by NBC News’ Gabe Gutierrez how Israeli tanks appearing to near central Gaza did not represent a full-scale ground operation, Kirby said Israeli officials had maintained that their tanks were moving along the Philadelphi Corridor, a key strategic strip of land running along the Egypt-Gaza border, and “not in the town proper.”

“That’s what the Israelis have said,” Kirby responded. “We’re going based on what the Israelis are telling us and what they’re saying publicly and what we’re able to discern, as best we can.”

Kirby’s comments came just days after an Israeli airstrike sparked a fire that tore through a tent camp in Rafah’s Tal al-Sultan neighborhood, killing at least 45 people including children according to local health officials.

The attack has added to growing international pressure after the United Nations’ top court ordered Israel to halt its offensive in Rafah. The United Nations Security Council could vote as early as Wednesday on a draft resolution circulated by Algeria ordering Israel to immediately stop its offensive and demanding a cease-fire in Gaza, according to the Associated Press news agency.

In a briefing Tuesday, Israel Defense Forces spokesman Rear Adm. Daniel Hagari said Israel was still investigating the strike, including what caused the fire that he said “resulted in this tragic loss of life.”

Hagari said the IDF fired two 17-kilogram (37.5-pound) munitions targeting two senior Hamas militants, but he said somehow a fire was ignited, adding that the blaze was “unexpected and unintended.”

He suggested the possibility that weapons stored in the area targeted might have ignited the fire, but said that was an “assumption” at this point. An Israeli official and U.S. official separately told NBC News it was possible a fuel tank was struck, igniting the blaze.

The images from the strike have piled pressure on the U.S. to act.

Asked during Tuesday’s White House briefing how many “charred corpses” Biden needed to see before changing policy, Kirby said he took “offense” to the question, saying: “We don’t want to see a single more innocent life taken.”

The U.S. had also warned Israel against launching a full-scale ground invasion of Gaza early in the war, after Israeli Prime Minister Benjamin Netanyahu publicly announced plans to do so.

But after months of publicizing plans for a full-scale invasion, Israeli ground troops quietly entered the Gaza Strip with little fanfare in late October, in a move that appeared to avoid drawing American ire. The IDF’s entry into Gaza marked the beginning of a monthslong ground offensive, however, in which more than 36,000 people have been killed, according to the Gaza Health Ministry.

Israel launched the offensive following Hamas’ Oct. 7 attacks, in which around 1,200 people were killed and some 250 others taken hostage, according to Israeli officials. Some 125 people are believed to remain held in Gaza, with at least around a third believed to be dead.

Biden’s warning over the U.S. “red line” is reminiscent of former President Barack Obama’s own use of the phrase in August 2012, when he issued a warning over the use of chemical weapons in the Syrian civil war.

Critics accused Obama of allowing that boundary to be crossed without action from the U.S., with political opponent John McCain saying the Obama administration’s red line appeared to be “written in disappearing ink.”