Amir Saeid Iravani, Iran’s ambassador to the UN, called Biden’s remarks “profoundly alarming and provocative” in a letter addressed to UN chief Antonio Guterres and the Swiss presidency of the UN Security Council.

The US president responded “yes and yes” when asked Friday by a reporter if he had “a good understanding right now” of how and when Israel would respond to Iran’s missile barrage on Oct 1.

Iran launched around 200 ballistic missiles at Israel in retaliation for the killing of Tehran-backed leaders belonging to Hamas and Hezbollah, and an Iranian Revolutionary Guard general.

US ally Israel, at war with Hamas in Gaza and Hezbollah in Lebanon, vowed revenge against Iran for the strikes.

“This inflammatory statement (of Biden) is deeply concerning, as it indicates the United States’ tacit approval and explicit support for Israel’s unlawful military aggression against Iran,” Iravani wrote in the letter.

“Therefore, the United States will bear full responsibility for its role in instigating, inciting and enabling any acts of aggression by Israel against the Islamic Republic of Iran, in flagrant violation of the fundamental principles of international law and the United Nations Charter,” he said.

According to the Washington Post, Israeli prime minister Benjamin Netanyahu has told Biden that he intends to strike Iran’s military sites, and not to target nuclear or oil infrastructure.