The U.K. Maritime Trade Operations Centre (UKMTO) said that a cargo ship reported being hit by an "unknown projectile" off the coast of Oman on Monday.

-ABC News' Will Gretsky

President Donald Trump said during an Oval Office signing event that this is Iran’s “last chance” to make a deal.

When asked about the number of times he’s called off strikes after threatening them, the president responded, “I don't know. I think we're going to maybe get something, but I want to give every last chance before decapitation.”

Trump said the first phase of a deal would open the Strait of Hormuz immediately. He said the second phase of the deal being negotiated now is Iran’s denuclearization, though he noted that phase would come later and “take a little while.”

Trump also suggested that Iran was swayed by the threat of Sunday night’s planned attacks, which Trump said would have been “harder” than “any” attack since World War II.

“But in this case, leakers helped because they said the severity of the attack, and Iran knew it. They knew what was coming. It was going to come last night, and it would have gone on for a long time, and there'd be essentially very little left. There'd be nothing left, and if I'm given a chance to let a lot of people live, I want to give that chance. So I'm under no time constraint,” Trump said.

Trump also insisted there will be no tolls charged in the Strait of Hormuz, but he added, “if anybody’s going to charge, we’ll charge.”

-ABC News’ Michelle Stoddart and Emily Chang

President Donald Trump is claiming that Iranian leaders are being “unbelievably duplicitous” in their public statements about negotiations with the U.S., writing on social media Monday that Iranian leaders “beg” for meetings and then publicly say they won’t have discussions.

"Whether Iran wants to admit it or not, we are, in fact, talking of a solution to a problem that they have caused, for decades," Trump said.

The president’s post comes after he said on Sunday that another round of negotiations would begin on Monday -- though Iran said no talks are underway.

Iranian foreign ministry spokesperson Esmaeil Baqaei reiterated Monday that ongoing talks with Oman are strictly about the Strait of Hormuz and that "the issues related to Iran and the United States should be examined in the next stages to see in which direction the situation will go."

Trump, in his post, appeared frustrated with Iran’s insistence that they’re “only dealing with” Oman.

“Iranian Leadership is unbelievably duplicitous! They ask for a meeting, some would say ‘beg,’ talks begin, with more scheduled in the immediate future, and they say, openly and proudly, that they’re not having any discussions, that nothing is being talked about, and they’re only dealing with ‘Oman,’” Trump wrote.

-ABC News’ Michelle Stoddart and Isabella Murray

Nine ships crossed the Strait of Hormuz on Sunday and 11 ships on Saturday, according to maritime intelligence firm Kpler. Seven of Sunday's nine crossings were conducted via the Iranian route in the northern part of the waterway, Kpler said.

The Bab el-Mandeb Strait -- which sits at the southern entrance to the Red Sea -- recorded 30 crossings on Sunday, down from 37 crossings on Saturday and 42 crossings on Friday, Kpler said.

"The diplomatic outlook is still unsettled. Until U.S., Iranian and Omani signals converge into clear navigation arrangements, operators should treat both chokepoints as contested rather than normalized," Kpler said.

-ABC News' Victoria Beaule