Washington (CNN) The US announced Friday it would send additional troops along with enhanced air and missile defense systems to Saudi Arabia and the United Arab Emirates in response to the attack on Saudi oil facilities, which the US has blamed on Tehran.

Describing the attack as a "dramatic escalation of Iranian aggression," Defense Secretary Mark Esper told reporters at the Pentagon that the troops would be "defensive in nature and primarily focused on air and missile defense" following the attacks on Saudi oil facilities attacks which Esper said "all indications are that Iran was responsible for."

"Right now we're focused on helping the Saudis improve their defense infrastructure," Esper said. The administration's goal is to send a "clear message" that the United States supports its partners in the region, will defend the free flow of commerce through the Persian Gulf and demonstrate its commitment to the rules-based international order.

"As the President has made clear, the United States does not seek conflict with Iran," Esper said, "that said, we have many other military options available should they be necessary."

Gen. Joseph Dunford, chairman of the Joint Chiefs of Staff, told reporters Friday the US hadn't "decided on specific units" for air defense assets but said "it would be capabilities to enhance their air and missile defense."

"It's now my job to come back to the Secretary with the details of what we believe would meet the Saudis' requirements and is sustainable," Dunford said.

New sanctions

The Pentagon announcement came hours after President Donald Trump announced that he had applied new sanctions on two pillars of the Iranian economy, the country's central bank and its sovereign wealth fund, days after the attack on a Saudi oil facility that the US has blamed on Tehran.

Speaking in the Oval Office, Trump said it would be easier for him to launch airstrikes, as some congressional Republicans and other hawks have advocated. Instead, the President cast his decision as taking the harder road and signaled later in the day that he's not considering a direct military response at the moment.

"I think the strong person approach, and the thing that does show strength, would be showing a little bit of restraint," he said, describing the penalties that will be applied to Iran's national bank as the "highest level" sanctions.

Since it left the Iran nuclear deal in May 2018, the Trump administration has been ramping up economic penalties as part of its "maximum pressure" campaign to bring Tehran to the negotiating table. On Friday, Trump pointed to the campaign's impact.

'Iran is going to hell'

Iran is "going to hell," Trump said. "It's too bad what's happened to Iran, it's going to hell, doing poorly, they're practically broke. They are broke. And they could solve the problem very easily. All they have to do is stop with the terror," Trump said.

Trump made the announcement as he prepared to meet with his national security council to weigh options for responding to the attack, which US officials say was carried out by drone and missiles and which affected 5% of the world's global oil supplies.

Iran has denied responsibility. Yemen-based Houthi rebels, locked in an ongoing war for control of the country with Saudi Arabia and its allies, have said they are behind the attack.

US officials have refused to accept that and insist Iran is responsible, though they have not yet presented evidence to support the claim.

"Iran's brazen attack against Saudi Arabia is unacceptable," Treasury Secretary Steven Mnuchin said in a statement about the new sanctions, which targeted the Central Bank for providing "billions of dollars to the Islamic Revolutionary Guards Corps, its Qods Force and its terrorist proxy, Hizballah."

"Treasury's action targets a crucial funding mechanism that the Iranian regime uses to support its terrorist network, including the Qods Force, Hizballah, and other militants that spread terror and destabilize the region."

The US has already targeted Iran's central bank, using Congressional authorities, for a variety of issues, including money laundering and missile activity. Friday's sanctions designated the Central Bank for terrorism, making them much harder for a future administration to lift. The bank would have to show it had stopped funding for Hezbollah or other terrorist groups.

"Targeting Iran's Central Bank is no ordinary sanction or penalty. It is a significant force multiplier for US coercive and punitive economic measures," said Behnam ben Talebu, a senior fellow at the Foundation for Defense of Democracies. "The question is, even in the face of such a powerful move, will America's allies across the Persian Gulf be satisfied with sanctions alone."

'Plenty of time'

During a White House press conference with the Australian Prime Minister Friday afternoon, Trump again said that he is showing great restraint in his actions against Iran.

"Going into Iran would be a very easy decision, as I said before, very easy," Trump said. "The easiest thing. Most people thought I would go in within two seconds but -- plenty of time. Plenty of time."

"I think I'm showing great restraint. A lot of people respect it. Some people don't," he continued. "I don't do it for anybody. I do it for what's good for the United States, what's good for our allies, and it's working out really, very well."

Some Middle Eastern allies are frustrated that Trump doesn't seem to be considering kinetic action against Iran -- an act that lawyers and academics say would violate international law, since the US was not attacked and so far, neither Washington nor Riyadh have proven that Iran was the perpetrator.

'Nothing else to sanction'

One diplomat from the region believes if the US does not respond forcefully to the Saudi oil field attack, its allies in the Middle East will question why the US has a presence there in the first place. And the diplomat expressed skepticism the new sanctions will have a significant impact.

"There is literally nothing else to sanction," the diplomat said.

Analysts disagreed, even as some said the biggest economic targets in banking and other industries have already been hit and that move against the central bank wouldn't have strong economic impact.

"There is no end to the sanctions designations that the US could roll out," said Elizabeth Rosenberg, a former Treasury official and now a senior fellow at Center for a New American Security. "Sometimes the sanctions with political ramifications can be more impactful than certain economic sanctions."

Rosenberg said the central bank sanctions wouldn't "meaningfully change the economic effect of the sanctions already in place, but it says to Iran and to the world that we are still going to exercise our economic muscle."

Mark Dubowitz, the chief executive of FDD, predicts there are more sanctions to come.

"I would expect we would see more," Dubowitz said. "The conventional wisdom out there that we've pretty much exhausted all the sanctions we can impose on Iran is completely false. There are many, many more things that can be done and there are many more actions in Treasury's pipeline. ... We may be at seven on the sanctions dial and maximum pressure requires an 11."

This story has been updated.