The Islamic Revolutionary Guard Corps said in a statement on Monday that its aerospace force launched a missile strike on petrochemical facilities in the northern Israeli city of Haifa in response to Israel's attack on Iranian petrochemical facilities, according to Iranian state television.

The IRGC statement said that striking civilian targets and oil facilities is a "dangerous game" which threatens all energy infrastructure in the region.

-ABC News' Somayeh Malekian

Iranian Foreign Ministry spokesperson Esmail Baghaei said during a press conference on Monday that the U.S. bears ultimate responsibility for any escalation between Iran and Israel, following their exchange of direct strikes on Sunday through into Monday.

"In our region, nobody believes that any action by Tel Aviv takes place without coordination with the United States," Baghaei said, as quoted by the official Islamic Republic News Agency.

"The United States' responsibility in the Israeli regime's acts of aggression is clear, and Washington will bear responsibility for the consequences of escalating tensions," he added. "Despite American claims, we know they are currently cooperating with Tel Aviv in both offensive and defensive operations."

Baghaei said that if the "basis of the negotiations," including the ceasefire in Lebanon, is violated by Israel or by the U.S., then the ongoing diplomatic process cannot continue.

"Attacks on our southern regions and the assault on Lebanon are being carried out under direct U.S. responsibility, and they must be held accountable for these crimes," Baghaei said.

Baghaei said Tehran will continue its "defensive measures" as long as it deems it necessary for the country's national security.

"We remain engaged in message exchanges with the United States," Baghaei said, warning that Tehran "cannot separate" Israeli and U.S. conduct.

"So far, our exchanges with the Americans have taken place in an atmosphere of deep mistrust, and the developments of the past 24 hours will only intensify that distrust," he added.

-ABC News' Somayeh Malekian

Iranian officials reported damage at a petrochemical plant in southwestern Iran and a military complex in northern Iran as a result of Israeli airstrikes, Iranian state media said.

The Israel Defense Forces said its air force struck "several targets" at a petrochemical plant in southwestern Iran. The semi-official Iranian Fars News outlet said that the region's deputy security officer confirmed the attack at the Karun Mahshahr Petrochemical Company and said part of the plant was damaged.

Iranian state news agency IRNA also cited local officials as saying no casualties had been reported after an attack on a military complex in the northern city of Tabriz.

-ABC News' Victoria Beaule

The Iran-aligned Houthi rebel group in Yemen on Monday claimed an attack on "sensitive Israeli targets."

In a statement on their Telegram channel, the Houthis also declared a ban on Israeli ships navigating in the Red Sea. "We affirm that we will respond to escalation with escalation, and our military operations will intensify in accordance with events," the statement read.

-ABC News' Victoria Beaule and Nasser Atta