U.S. Central Command is denying Iran's claim that the Strait of Hormuz is closed, saying that commercial ships continue to transit in and out of the waterway.

Iran vowed to "give a crushing and decisive response" to the U.S. strikes, according to Iran's Fars News Agency state media.

The Islamic Revolutionary Guard Corps claimed it has completely closed the Strait of Hormuz due to U.S. strikes in Iran.

The IRGC said the strait is "declared closed to all vessels, including oil tankers and commercial ships, due to security concerns, and any passage will be targeted," according to a statement published by state media.

The strait is closed until further notice, the IRGC Navy said while alleging the U.S. has repeatedly violated the ceasefire.

Ahead of the latest round of U.S. strikes, President Donald Trump huddled with key members of his national security team to discuss the scope of the attacks as well as the anticipated impact on negotiations, according to two U.S. officials.

One official said that Secretary of State Marco Rubio and other top administration officials have been in contact with their counterparts in the Gulf states as they brace for what is widely expected to be a larger retaliatory response from Iran than what occurred Tuesday.

Another official said the Qatari delegation that traveled to Iran earlier (and has since left) did so as part of a last-ditch effort to preserve what remained of the ceasefire, but that they were unable to demonstrate enough meaningful progress to make a case for more time.

The Qatari mediators are expected to keep the lines of communication open as the administration ratchets up kinetic pressure on Iran to come to the table.

-ABC News' Shannon Kingston

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