Secretary of State Marco Rubio pressed for the opening of the Strait of Hormuz as soon as an agreement with Iran is reached, saying the strait will be open, "one way or the other."

During a gaggle with reporters during his multi-nation diplomatic tour, Rubio said that there is not a country in the world that favors Iran's self-imposed "tolling system," calling it, "unacceptable," and "unsustainable for the world."

"What's happening there is unlawful. It's illegal. It's unsustainable for the world. It's unacceptable," Rubio said, adding: "The Russians are not in favor of a tolling system. The Chinese are not in favor of a tolling system. I mean, there's no country in the world that's in favor of a tolling system, except the regime in Iran."

Regarding the emerging potential deal between the U.S. and Iran, Rubio said that while there is support for a preliminary draft from a "number" of regional leaders, it will take a "couple of days," to come to an agreement.

"The president had a very important, I think, historic call just a couple days ago with a number of leaders from the region. I think there's strong alignment and agreement on what a preliminary draft should look like," Rubio said. "I think, like anything with something like this, it's going to take a couple days to settle on … If there's going to be a deal, we're going to have to work through that, but this is, you know, it's either going to be a good deal or there isn't going to be one."

U.S. forces on Monday launched what U.S. Central Command described as "self-defense strikes" in southern Iran.

"U.S. forces conducted self-defense strikes in southern Iran today to protect our troops from threats posed by Iranian forces," CENTCOM spokesperson Capt. Tim Hawkins said in a statement. "Targets included missile launch sites and Iranian boats attempting to emplace mines. U.S. Central Command continues to defend our forces while using restraint during the ongoing ceasefire."

The strikes were conducted in the area of Bandar Abbas, which is where Iran's main naval base is located, according to Hawkins.

A U.S. official described the scope of the strikes as "very small."

-ABC News' Steven Beynon

President Donald Trump said Iran's enriched uranium can be turned and destroyed in the U.S., but that his preference is for it to be destroyed "in place" or at "another acceptable location," with IAEA oversight.

“The Enriched Uranium (Nuclear Dust!) will either be immediately turned over to the United States to be brought home and destroyed or, preferably, in conjunction and coordination with the Islamic Republic of Iran, destroyed in place or, at another acceptable location, with the Atomic Energy Commission, or its equivalent, being witness to this process and event,” Trump said in a post on his social media platform.

This presents a shift as Trump has long demanded that Iran hand over its enriched uranium to the U.S. as a sticking point of any potential deal.

In April, Trump said: "The U.S.A. will get all Nuclear 'Dust,' created by our great B2 Bombers - No money will exchange hands in any way, shape, or form."

Last week, Trump said that getting the enriched uranium is important for the U.S. "psychologically."

Trump has also repeatedly insisted that Iran has admitted to him that only the U.S. has the capability to uncover and obtain the so-called "nuclear dust."

-ABC News' Emily Chang

Israeli Prime Minister Benjamin Netanyahu said Israel will "intensify" strikes in Lebanon.

"We are not taking our foot off the gas. On the contrary, I have instructed them to press the pedal even harder," he said in a video message on Monday.

"What is required from us now is to intensify the blows, increase the force," he said. "We will strike them decisively."

The message comes as the Israel Defense Forces said Monday it struck more than 70 "Hezbollah infrastructure sites" across Lebanon.