Iran on Thursday denounced the US government and Congress for welcoming the Israeli prime minister amid the deadly war in Gaza that is raging into its 10th month.

"Palestinian children are slaughtered every day by the Tel Aviv butcher, and in the face of all these crimes, the American government and Congress are welcoming this executioner with applause," said Iran's foreign ministry spokesman Nasser Kanani in a post on X.

"The criminal prime minister of a fake regime is embraced by his supporters after nine months of genocide and infanticide," he added, referring to Benjamin Netanyahu, who addressed the US congress on Wednesday.

The remarks came after Netanyahu called for an alliance against what he described as an Iranian "axis of terror", claiming Tehran is behind almost all sectarian killing in the Middle East.

"America and Israel today can forge a security alliance in the Middle East to counter the growing Iranian threat," he told US lawmakers.

The months-long Gaza war was triggered when Palestinian militant group Hamas launched a surprise attack on Israel on October 7, resulting in the deaths of 1,197 people, mostly civilians, according to an AFP tally based on Israeli figures.

Out of 251 people taken hostage that day, 111 are still being held inside the Gaza Strip, including 39 who the military says are dead.

More than 39,100 Palestinians have been killed in Israel's military campaign in the Gaza Strip since the war began, according to the health ministry of Hamas-run Gaza.

Iran had hailed the October 7 attack but said it was not involved in it.