Huge American flag-burning protests have erupted across the Middle East as Iranian protesters gather to condemn the Israeli airstrike against Iran's consulate in Syria on Monday.

Photos and videos show large groups of protesters shouting anti-Israeli and anti-US slogans in Tehran while burning US and Israeli flags in a show of frustration and anger.

The protests come after a strike widely attributed to Israel demolished Iran's consulate in Damascus on Monday and killed eight people, including two Iranian generals. Israel has refused to comment on the airstrike.

Iran and one of its key proxies vowed on Tuesday to respond to the attack, as the country's Supreme National Security Council met to decide on a "required" response.

Iran's state TV reported the meeting was chaired by President Ebrahim Rais but provided no further details.

Supreme Leader Ayatollah Ali Khamenei, who has final say on all matters of state in Iran, said: "We will make them regretful about the crime and similar acts."

Israel has repeatedly targeted military officials from Iran, which supports militant groups fighting Israel in Gaza. The strike in Damascus on Monday escalated the conflict because it struck an Iranian diplomatic mission.

According to the US National Security Council, the US did not know of the strike in Damascus ahead of time and played no role in the attack.