The United Kingdom Maritime Trade Operations (UKMTO) Centre on Tuesday reported that a vessel was "struck by an unknown projectile" in the Strait of Hormuz.

The incident occurred on Monday evening, the UKMTO said in its alert. "There is no reported damage or environmental impact. Authorities are investigating," the message read.

Thirteen civilians were injured in Houthi strikes on Saudi Arabia on Monday, according to the spokesman for the Saudi Coalition Forces.

Civilian infrastructure in the cities of Khamis Mushait, Abha and Taif were struck by ballistic missiles and drones, with seven homes damaged, the spokesman said.

The Saudi military will "deal with these attacks responsibly and decisively," the spokesman said.

The Pentagon's Inspector General said in a report released Monday that the Pentagon acknowledged that the war in Iran has resulted in munitions shortfalls.

The "munitions expenditure in [Operation Epic Fury] has resulted in strategic inventory shortfalls and revealed industrial base bottlenecks for munitions resupply," including the building of solid rocket motors, explosives and propellants, the report stated.

The Defense Department is "working to streamline procurement processes and production lead times, and to stockpile critical materials, components, and selected munitions to respond rapidly to a contingency," the report stated.

The information was provided by the Defense Department in written responses sent to the Inspector General on Aug. 26, according to the report.

The Defense Department estimated the cost of the war to be $33.4 billion as of June 29, according to the report. The estimate included $7.4 billion of cumulative obligations, $22.3 billion for expended munitions and $3.7 billion in equipment losses, it said.

U.S. Central Command reported that Iranian strikes "damaged and destroyed hundreds of buildings and structures" at U.S. bases in the Middle East, according to the report.

U.S. diplomatic facilities in the region have also suffered $184 million in damage from Iranian strikes, the report said.

-ABC News' Luis Martinez

The secretary of Iran's Supreme National Security Council said that it won't negotiate "until Iran's conditions are met," according to a statement published by Iranian state media.

"The equations regarding oil and the Straits have changed," the statement continued.

The statement comes after President Donald Trump said Monday that Iran "wants to make a deal, quickly and badly" and that the U.S. is "open" to the "concept" of negotiating.

The Iran-backed Houthi rebels in Yemen on Monday claimed to have launched a "wide-scale military operation" targeting the King Khalid Air Base in southwestern Saudi Arabia.

In a statement posted to Telegram, Houthi spokesperson Yahya Saree said the group used "dozens of ballistic missiles and drones" to attack the air base in the city of Khamis Mushait, with targets including hangars housing combat aircraft, radars, runways and ammunition depots.

The Saudi Defense Ministry did not immediately comment on the Houthi claim.

Saree said the latest Houthi strikes were in part a response to the recent intensification of Saudi airstrikes against the group. Saudi aircraft, he said, have conducted more than 300 strikes in the last five days.