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'Specific, credible' Iran threat against US forces triggered carrier deployment, sources say

Washington(CNN) "Specific and credible" intelligence that suggested Iranian forces and proxies were targeting US forces in Syria, Iraq and at sea led the Pentagon to recommend a carrier strike group be moved to the region, two US officials tell CNN.

The Pentagon and Central Command asked the White House to announce the military moves to give added heft to the new orders and send a message to Tehran, according to multiple military and US officials.

The strike group's deployment from the Adriatic Sea to the Strait of Hormuz is aimed specifically at deterring any Iranian military actions, a senior military official added. The Strait, a 21-mile wide waterway that separates Iran from other Gulf countries, is the conduit for shipments of about 30 percent of the world's crude oil, making it a strategically crucial passageway for the global economy.

Iran explicitly warned the US in April against any moves to block or interfere with the Strait.

While Iran has made threats in the past, the officials said the scope of this latest set made military commanders strongly believe they needed to make both an urgent request for additional military forces and then make a public statement about sending that deterrent force to the region.

'Had to be taken seriously'

"There was enough information to indicate this had to be taken seriously," one of the officials said. Administration officials have provided no detail publicly on the nature or extent of the threat.

National Security Adviser John Bolton said in a written statement Sunday that the US is not seeking war with Iran, but was deploying the USS Abraham Lincoln Carrier Strike Group as well as a bomber task force to the US Central Command region in the Middle East "to send a clear and unmistakable message to the Iranian regime that any attack on United States interests or on those of our allies will be met with unrelenting force."

A source close to Bolton told CNN that the move was based on intelligence about threats to US personnel or allies. The first US official with direct knowledge of the situation told CNN the threats were against both US maritime and land-based forces in the Middle East.

The strike group had been on a regular deployment to support maritime security operations in international waters in the Adriatic Sea before receiving the new orders Sunday to redeploy, two US officials told CNN. The group is currently in the eastern Mediterranean. After it transits through the Suez Canal, it will take about a day and half to arrive just outside the Strait of Hormuz.

Bolton said Sunday that the US was acting "in response to a number of troubling and escalatory indications and warnings."

That intelligence came to light over the weekend, the US officials said, leading to high level conversations between the White House, the Pentagon and US Central Command on how to proceed.

Secretary of State Michael Pompeo, speaking to reporters Sunday, said the deployment was "something we've been working on for a little while."

He added that "it is absolutely the case that we have seen escalatory actions from the Iranians and it is equally the case that we will hold the Iranians accountable for attacks on American interests."

The deployment is the latest step in the Trump administration's increasingly intense maximum pressure campaign against Tehran. It comes almost a year after Pompeo gave a speech in which he laid out 12 ways the US insists Iran must change and start being a "normal" country -- a speech that many saw as a call for regime change in everything but name.

The US is 'fully prepared'

The deployment follows a move to cut off Iran's oil revenues, its chief source of foreign income, curb its civilian nuclear work, and designate Iran's Revolutionary Guard Corps, the elite military group which has deep political and economic influence in the country, as a terrorist entity.

The source close to Bolton said the deployment is meant as a warning. The decision to have the national security adviser make the announcement, and not acting Defense Secretary Patrick Shanahan, was meant to clearly convey the fact it was a warning, the source said. Separately, the source said Bolton supported the decision to make this move.

Bolton said in a statement Sunday that the US is "fully prepared to respond to any attack, whether by proxy, the Islamic Revolutionary Guard Corps, or regular Iranian forces," which offered no detail about the nature of the threats or when the intelligence was received.

The national security adviser has long called for the overthrow of the Iranian regime, a point Iranian Foreign Minister Javad Zarif alluded to recently in New York when he predicted that Iran hawks would seek to orchestrate a clash.

Referring to Bolton, as well as Israeli Prime Minister Benjamin Netanyahu and the crown princes of the United Arab Emirates and Saudi Arabia, as the "B Team," Zarif said Trump's efforts to bully Iran into renegotiating the 2015 nuclear deal won't work.

"Then, Plan B of the B Team will come in to play," he said at the Asia Society on April 23. "I believe the B Team does not have the same plan as President Trump has... not a plan but a plot that will cost" trillions, Zarif said, alluding to the cost of US wars in the Middle East.

"The plot is to push Iran into taking action. And then use that," Zarif said.

Since the US decision to end waivers that allowed other countries to import Iranian oil without fear of sanctions, an administration official told CNN there are concerns Tehran could target US assets in the Middle East and escalate tensions with Washington and in the region.

Analysts, US allies and others have expressed similar concerns since the administration began its maximum pressure campaign. Iran's possible retaliation against US pressure tactics could include increasing its short and medium-range missile tests, increasing the detention of dual nationals, resuming the harassment of US Navy vessels in the Persian Gulf, cyber-attacks against the US or its allies, and using proxies to attack US interests or American allies.

Prepare for consequences

Some analysts have speculated that Iran could also disrupt shipping in the Strait of Hormuz, but most dismiss that possibility because the waterway is crucial to Iran's economy.

In April at the Asia Society, Zarif said that Iran will keep working to export oil and not interfere in the Strait of Hormuz.

"We will continue to find buyers for our oil. And we will continue to use the Strait of Hormuz as a safe transit passage for the sale of our oil," Zarif said. "But if the United States takes the crazy measure of trying to prevent us from doing that, then it should be prepared for consequences."

"It is in our interest, our vital national security interest, to keep the Persian Gulf open, to keep the Strait of Hormuz open," Zarif said. "But the United States should know when they enter the Strait of Hormuz, they have to talk to those who are protecting the Strait of Hormuz, and that is Iranian Revolutionary Guards."

Pompeo said Monday that the US continues to see Iranian activity "that leads us to believe that there's escalation that may be taking place."

"So we're taking all the appropriate actions both from a security perspective, as well as our ability to make sure that the President has a wide range of options in the event that something should actually take place," Pompeo said in Rovaniemi, Finland.

Asked about the possibility that Iran could pull out of the Iran nuclear deal, and accusations that the Trump administration has been pushing for this, Pompeo did not directly answer. "What we've been trying to do is to get Iran to behave like a normal nation," he said.

'12 Elements'

"We laid out 12 elements of that," Pompeo said, referring to his 2018 speech. "Every single one of the elements is consistent with what we ask every other country around the world to do," Pompeo continued, "things like not conducting assassination campaigns around the world, not sponsoring terror organizations that inflict missile attacks on Israel, now 600 plus, not building missile systems in Yemen."

"These are things we ask every country to do. That's our objective," he continued. When Iran behaves like a "normal nation," then "we'll welcome them back," Pompeo said, adding that the US is "happy to engage" if a negotiation needs to take place.

Asked whether the US is facing threats from Iran or proxy forces in Iraq, Pompeo said that as Secretary of State, he had the duty to keep US personnel safe around the world.

"That includes in Erbil and Baghdad, in our facilities in Amman, all around the Middle East," Pompeo said.

CNN's Jennifer Hansler and Kylie Atwood contributed to this report