President Joe Biden said for the first time he would halt some shipments of American weapons to Israel, which he acknowledged have been used to kill civilians in Gaza if Prime Minister Benjamin Netanyahu orders a major invasion of the city of Rafah.

Biden announced that he was prepared to condition American weaponry on Israel’s actions amounts to a turning point in the seven-month conflict between Israel and Hamas. And his acknowledgement that American bombs had been used to kill civilians in Gaza was a stark recognition of the United States’ role in the war.

He said he has come under extraordinary pressure, including from members of his own party, to limit shipments of arms amid a humanitarian crisis in Gaza and until now, the president had resisted those calls and strongly supported Israel’s efforts to go after Hamas. Yet a looming invasion of Rafah, the city in southern Gaza where more than a million Palestinian civilians have been sheltering, appears to have shifted the president’s calculus.