JERUSALEM, May 9 — Israel’s ambassador to the United Nations expressed disappointment today at US President Joe Biden’s threat to stop certain arms supplies to Israel if it invades the crowded Gaza city of Rafah.

“This is a difficult and very disappointing statement to hear from a president to whom we have been grateful since the beginning of the war,” Gilad Erdan told Israeli public broadcaster Kan radio, in Israel’s first reaction to Biden’s warning.