Biden told reporters he delivered a message to Iran, and the country’s leaders know not to get involved. He also said he viewed Thursday’s strike as successful.

“I don’t think there’s any civilian casualties. That’s another reason why it’s a success,” he said.

The president delivered his remarks during his Friday tour of Pennsylvania to tout the economic recovery in Allentown under his administration.

American and British airstrikes in Yemen killed at least five Houthi rebels and wounded at least six others, the group’s military spokesman confirmed Friday.

Brig. Gen. Yahya Saree said six people were injured in addition to the five deaths from the 73 attacks carried out by U.S. and British forces Thursday, while pledging that the Houthis would respond.

“The American and British enemy bears full responsibility for its criminal aggression against our Yemeni people, and it will not go unanswered and unpunished,” Saree said.

The Houthi group’s Supreme Political Council also said in a statement that “all American-British interests have become legitimate targets.”

The Iran-backed Houthi group also said it would continue attacking commercial ships traveling through the Red Sea, claiming those attacks are meant to block “transit of Israeli ships or those carrying goods to the occupied Palestinian ports.”

Houthi authorities also warned of “a heavy price” to be paid by the United States and Britain.

The retaliatory strikes in Houthi-controlled areas of Yemen came after several Houthi attacks in the Red Sea late Thursday. Houthi militants have been consistently attacking foreign ships in the Red Sea for months. At least 27 attacks on commercial shipping vessels in the Red Sea have occurred since Nov. 19, the U.S. Central Command said.

American and British forces Thursday used a combination of land, air and sea-based military platforms to launch their offensive, including destroyers and at least one submarine from the U.S. Navy.

Speaking to reporters in Ukraine, British Prime Minister Rishi Sunak stood by the decision, calling the jointly conducted missile attacks necessary and justified.

“We’ve seen a significant increase in the number of Houthi attacks…that’s putting innocent lives at risk. It’s disrupting the global economy, and it’s also destabilizing the region,” Sunak said Friday.

“And it’s why I made the decision with allies to take what I believe to be necessary, proportionate and targeted action against military targets, to degrade and disrupt Houthi capability. It’s clear that this type of behavior can’t be met without a response. We need to send a strong signal that this breach of international law is wrong.”

British Armed Forces Minister James Heappey added that additional airstrikes were not “immediately planned.”

Reaction from U.S. politicians to Friday’s news was divided among Republicans, with Rep. Marjorie Taylor Greene, R- Ga., on social media calling the campaign “insanely out of control.”

Senate minority leader Mitch McConnell, R-Ky., praised the move.

“President Biden’s decision to use military force against these Iranian proxies is overdue,” McConnell said in a statement.

“I am hopeful these operations mark an enduring shift in the Biden administration’s approach to Iran and its proxies. To restore deterrence and change Iran’s calculus, Iranian leaders themselves must believe that they will pay a meaningful price unless they abandon their worldwide campaign of terror.”

Meanwhile, the U.S. Treasury Department on Friday sanctioned two foreign companies for doing business with an Iranian-backed Houthi financial facilitator.

The Treasury’s Office of Foreign Assets Control sanctioned a Hong Kong-based company, as well as one in the United Arab Emirates for shipping Iranian commodities.

Revenue generated by both is used to “fund the Houthis and facilitate their attacks,” the Treasury said in a statement.