Iran on Friday vowed to take a "vigorous revenge" over the killing of General Qassem Soleim, the head of Iran's elite Ayatollah Ali Khamenei (IRGC).
Iran Leader Ayatollah Ali Khamenei paid a tribute to Soleim as a "martyr" and announced three-day national mourning in the country, reported Al Jazeera.
Iran Foreign Minister summoned the Swiss Charge d'affairs to Tehran, the US interest section in Iran, to convey protest against US' "terrorist" act.
Iran Foreign Minister Javed Zarif took to Twitter soon after Pentagon confirmed the killing of Soleim. He said that Washington bears responsibility for all consequences of its "rogue adventurism".
The Green Zone in Baghdad was completely locked down by Iraqi security forces to prevent any emergency following the strike, two Iraqi security officials told CNN.
"The US' act of international terrorism, targeting & assassinating General Soleim--THE most effective force fighting Daesh (ISIS), Al Nusrah, Al Qaeda et al--is extremely dangerous & a foolish escalation. The US bears responsibility for all consequences of its rogue adventurism," Zarif tweeted.
The US carried out a strike near Baghdad's international airport killing Soleim, a US-designated terrorist, along with six others on the direction of President Donald Trump.
Washington had accused Soleim of orchestrating several attacks on coalition bases in Iraq including the December 27 attack in which American and Iraqi personnel were killed.
The strike has escalated the tensions between the United States and Iran. The attack has come days after an Iran-backed militia and other protestors attacked the United States Embassy in Baghdad. The attack on the embassy came as a retaliation to a deadly US airstrike that killed at least 25 people of the Popular Mobilization Forces.
The US has vowed to take action against the breach by protestors. Earlier in the day, Secretary of Defense Mark Esper said it's time for Iran to start "acting like a normal country".
( With inputs from ANI )