Another retaliatory U.S. airstrike in the Middle East -- the first of its kind in Iraq -- ratcheted up tensions in the region Wednesday as casualties among Iranian-backed forces mounted and one militia group vowed retaliation.

A U.S. defense official confirmed to Military.com on Wednesday that fighter aircraft conducted precision airstrikes against two facilities used by a Hezbollah militia to support recent attacks on bases used by U.S. forces in Iraq and Syria.

The strikes, which were carried out in Iraq, came just a day after Iran-backed fighters shot ballistic missiles at Al Asad Air Base in western Iraq, prompting a response by a nearby U.S. AC-130 gunship against a vehicle near the launch site, killing some fighters.

According to the defense official, Tuesday's strikes were conducted against Kata'ib Hezbollah, an Iraqi Shia militant group that, according to U.S. intelligence, has thousands of members and seeks to establish an Iran-aligned government in Iraq.

The strikes targeted an operations center and a command-and-control node south of Baghdad, the official said. They also added that the initial evaluation indicated that "U.S. forces successfully destroyed the intended facilities." But while they confirmed the presence of Kata'ib Hezbollah personnel, "we're unable to provide a casualty assessment at this time."

In a statement reported by The Associated Press, Kata'ib Hezbollah said it was considering "expanding the scope of targets" if the U.S. strikes continued, adding that the most recent attack "will not go unpunished."

The most recent U.S. strike -- the first planned retaliation in the country -- also angered the Iraqi prime minister who, in a statement reported by several media outlets, called the attack a violation of the country's sovereignty and breach of the longtime U.S. mission to combat the Islamic State terrorist group on Iraqi soil.

Attacks against bases housing U.S. troops in the region have been near constant since Oct. 17, with at least 66 rocket and drone attacks that have injured at least 62 service members. Since that time, Pentagon officials have been forced to walk a thin line between proportionally responding to attacks on U.S. troops that, while generally ineffective, have led to injuries and damage but without escalating into a deeper conflict.

Officials such as Pentagon spokeswoman Sabrina Singh said as recently as Tuesday that U.S. retaliations have been precise and aimed solely at the groups they believe are responsible for attacking American bases.

However, despite the messaging, the pace of attacks and U.S. retaliation appeared to be growing. The first planned, retaliatory airstrike was conducted by U.S. jets on Oct. 27 in Syria. Since then, two more strikes have been conducted in that country.

Singh also revealed Tuesday that U.S. forces have been taking undisclosed but smaller-scale retaliatory actions whenever possible.

"We have had other cases where we have responded in retaliation when we were able to identify the point of origin" of the attack, she said.

Tuesday's AC-130 gunship strike was one such action.

Meanwhile, the U.S. presence in the region has grown dramatically since Hamas, which rules the Gaza Strip, launched a brutal and bloody surprise attack on Israel on Oct. 7 that left about 1,400 Israelis dead.

A separate defense official confirmed to Military.com on Monday that the aircraft carrier USS Gerald R. Ford, which has been in the waters off of Israel since the start of the conflict, has had its deployment extended.

When Military.com asked whether there was a limit to how long the Pentagon plans to keep the Ford on deployment -- which is now nearing 7 months in length -- Singh had no firm answer.

Defense Secretary Lloyd Austin "will make that [decision] when he determines that it's time for the Ford to come home," Singh said Tuesday.

Meanwhile, defense officials say that they will continue to message Iran that they plan to hold it accountable for the attacks of the militias it backs.

"We will not hesitate to take further measures to protect our people, if necessary," a defense official told Military.com.