Iran fired more than a dozen ballistic missiles early Wednesday targeting two Iraqi air bases that house U.S. troops, a move that came after Iranian leaders threatened to retaliate against the United States for a U.S. airstrike that killed a top Iranian commander.
Iran's Supreme Leader Ayatollah Ali Khamenei called the Iranian strikes a "slap in the face" to the United States, and said the "corrupt presence" of the U.S. in the region should come to an end.
Iranian President Hassan Rouhani added later in a tweet that Iran's "final answer" to the killing of Quds force commander Qassem Soleimani "will be to kick all U.S. forces out of the region."
Trump to address nation (*VOA will stream the announcement LIVE)
U.S. President Donald Trump planned to give his response to the missile strikes in a Wednesday morning statement.
Hours after the attack, Trump tweeted that an assessment of casualties and damage was taking place, but that "So far, so good!"
"We have the most powerful and well equipped military anywhere in the world, by far!" he said.
No casualties reported
The Iraqi prime minister's office said there were no casualties among Iraqi forces, and that it had not received reports of any casualties from the U.S.-led coalition.
The statement said Iran notified Iraq that it was carrying out its response to the U.S. strike.
Iraq also rejected any violation of its sovereignty and aggression on its territory, and called for restraint to prevent the U.S.-Iran crisis from developing into a devastating war.
Iranian Foreign Minister Mohammad Javad Zarif wrote in a tweet after the missile strikes that Iran had taken and concluded "proportionate measures in self defense."
The missile attack was the latest step in a series of events that have unfolded in the past two weeks with increasing tensions between the United States and Iran.
What led to missile strike
The U.S. blamed an Iran-backed militia for a rocket attack on an Iraqi base that killed a U.S. military contractor. U.S. airstrikes then hit that militia's positions in Iraq and Syria, drawing complaints from the Iraqi government and militia-led demonstrations at the U.S. Embassy in Baghdad. On Friday, a U.S. airstrike killed near Baghdad's airport.
A Pentagon spokesman said the missiles launched from Iran targeted the Al-Asad base, located about 60 kilometers west of Baghdad, as well as one in Irbil, part of Iraq's semiautonomous Kurdish region.
Reaction in Iran, US
Iran's Islamic Revolutionary Guard Corps sent out a statement hailing what it says was a successful missile attack on Iraqi bases housing U.S. troops, calling it "revenge for the assassination and martyrdom of Qassem Soleimani."
U.S. forces have been on high alert since Iran threatened to strike back after last week's targeted killing of Soleimani.
"We will take all necessary measures to protect and defend U.S. personnel, partners, and allies in the region," the Pentagon spokesman said.
Eliot Engel, chairman of the House Foreign Affairs Committee, told CNN that "The President and his crew better figure out a way to tone things down, because we could be in the midst of a full-blown war."
"What we have to do now is tone down the rhetoric on all sides and extricate ourselves from this situation," he added.
Steven David, a professor at Johns Hopkins University, told VOA the potential for the situation is "very frightening" with two leaders and countries that do not want to back down, and which are armed with all kinds of physical and cyber weapons.
"On the other hand, I do hope that at some point both sides simmer down and allow this to de-escalate," David said. "There's a lot of Iran can do in the area. It can attack Saudi Arabia, it can attack Israel, especially with cyber, it can attack America. Neither country wants this to get out of hand, and to me, that's the most people positive sign in this horrible mess."
Calls for de-escalation
Tom Warrick, a non-resident senior fellow at the Atlantic Council, noted officials from many nations around the world have called on the United States and Iran to de-escalate, and pointed the role Iraq may play going forward as the country where the back-and-forth attacks have taken place.
"What we're faced with is a situation where I believe that Iraq is going to go to the United Nations and demand that the United Nations put together some kind of process that will get Iraq out of the middle of the dispute between the United States and Iran," Warrick told VOA. "And we'll have to see whether the diplomats in New York can come up with a way that tries to get the countries talking rather than fighting."
Jeff Seldin and Jesse Oni contributed to this report.
WATCH: How Ballistic Missiles work