Iranian President Hassan Rouhani condemned US move to blacklist the IRGC, slamming the United States as the real "leader of world terrorism".
"Who are you to label revolutionary institutions as terrorists?" Rouhani asked in a televised speech on Tuesday. He added: "You want to use terrorist groups as tools against the nations of the region… you are the leader of world terrorism."
He went on to describe the IRGC as protectors of the Islamic republic. "The Guards have sacrificed their lives to protect our people, our (1979 Islamic) revolution… today America that holds a grudge against the Guards, blacklists the Guards."
A 'Gift to Netanyahu'
Hihg-profile Iranian diplomats have struck a similar tone, suggesting that this move was meant to bolster Netanyahu's electoral odds in Tuesday's national vote.
"Rushing to announce the decision in days when the Revolutionary Guards is busy rescuing flood-hit [Iranian] people is just a gift to Netanyahu to help him in the Israeli elections," tweeted Iran's envoy to the UK Hamid Baeidinejad.
His comments came just minutes after Foreign Minister Javad Zarif called the US decision "another election-eve gift to Netanyahu". Zarif earlier warned that Israel was seeking to drag the US into "another disaster" in the Middle East.
US President Donald Trump announced on Monday that his administration was formally designating the IRGC, the influential elite wing of Iran's military, a foreign terrorist organisation.
In retaliation against US actions, the Iranian Supreme National Security Council listed US Central Command (CENCTOM) as a terrorist organisation.
This designation came as another step in US efforts to clamp down on Iran's influence in the region, following the withdrawal from the 2015 nuclear deal and the re-imposition of crippling economic sanctions on the Islamic Republic.
Last month, Trump formally recognised Israel's sovereignty over the Golan Heights, a strategically-important area that the Jewish state took over from Syria in 1969, drawing condemnation from the United Nations and winning praise from Tel Aviv.
READ MORE: IRGC 'Terror' Labeling Could Enable US to Launch War Against Iran — Analysts
Benjamin Netanyahu, the prime minister of Iran's arch-foe in the Middle East, who has long accused Iran of supporting terrorism and threatening regional stability, praised the IRGC terror designation, which he said was made at his request.
Israel is holding its parliamentary election on Tuesday, where Netanyahu's Likud party is in a tight race with ex-army chief Benny Gantz's centrist Blue and White alliance. The situation somewhat resembles the November mid-terms in the US, as the Israeli election is widely seen as a nationwide referendum on Netanyahu. The prime minister, who has faced accusations of corruption, is looking to win a fourth consecutive term and fifth overall, which would make him the nation's longest-serving leader.