In an exclusive interview with CNN in Tehran, the advisor – Maj. Gen. Hossein Dehghan – was the most specific and direct threat so far by a senior Iranian official after General Qasem Soleimani was killed in a U.S. drone attack in Baghdad.
Dehghan is a former defense minister and now Ayatollah Ali Khamenei's primary military advisor. He told CNN that reprisals would come from Iran itself, not from the region's allied militia.
"It could be argued that there could be proxy operations. We can say that America, Mr. Trump, acted directly against us – so we act directly against America."
The United States has a growing military presence in the region. Thousands of US troops have been deployed to Saudi Arabia and around 5,000 are based in Iraq. The United States also has a large air base in Qatar and a naval presence in Bahrain, as well as troops based in Jordan, Kuwait and the United Arab Emirates.
Together with other Iranian officials, Dehghan suggested that Iran was in no hurry to take revenge and would choose its targets carefully. "Our reaction will be smart, thoughtful and timely with a decisive deterrent effect."
Iranian President Hassan Rouhani previously said that the Americans would have consequences for Soleimani's death "not only today, but also in the years to come."
Given the rhetoric of both sides, the danger of the escalation of the most dangerous confrontation between the United States and Iran for decades is growing.
The President continued, "They attacked us and we struck back. If they attack again, which I would strongly advise, we will hit them harder than ever!"
Dehghan defiantly responded to Trump's warning.
"It was America that started the war, so they should accept adequate reactions to their actions," he said.
"The only thing that can end this war period is that the Americans receive a blow that matches the blow they caused. They shouldn't look for a new cycle after that."
In the past few months, officials from the Trump administration and even the President himself have held out the prospect of renewed dialogue with Iran. Dehghan rejected this option.
"Look, we didn't want to negotiate with this incumbent US government for several reasons. After what happened to Mr. Soleimani, there is no need for negotiations or relationships. It is impossible."
"Gangster and a player"
Dehgahn also responded to Trump's threat to include Iranian cultural sites among the 52 targets the United States had chosen in the event of Iranian retaliation. The number was chosen to match the number of hostages arrested when the U.S. embassy took over in 1979, Trump said.
Dehghan said the tweets are ridiculous and absurd. "When he says 52, we say 300 – and they're accessible to us," said Dehghan. "No American military staff, no American political center, no American military base, no American ship will be safe.
"He doesn't know international law. He doesn't recognize UN resolutions either. Basically he's a real gangster and a player."
At one point in the interview, Dehghan pulled out a picture of Soleimani and held it in front of the camera.
"All Iranians are Qasem Soleimani," he said, insisting that the Quds force that Soleimani had led since 2003 would not be weakened by his death. The Quds were responsible for projecting Iranian influence in the Middle East and beyond, and played an important role in supporting the Assad regime in Syria.
"The person who replaced him has worked with him for two decades. He does the same thing," said Dehghan.
Iran's will to defend its interests "has increased a thousand times. We feel nothing. We have a logic, the logic of martyrdom."
As the war of words escalated, Dehghan repeated the comments of other senior Iranian officials that the country was not looking for war.
"Let me say one thing: Our leadership has officially announced that we have never sought war and that we will not seek war."
But his request that the United States not respond to Iranian reprisals over Soleimani's murder will certainly fall on deaf ears. This cycle of violence accelerated when a US contractor was killed in a missile attack on a joint Iraqi military base on December 29.
US officials held a pro-Iranian militia responsible for the attack. Their leader was killed along with Soleimani in the US drone attack in Baghdad.
CNN's Radina Gigova, Tamara Qiblawi, Jason Hanna and Steve Almasy all contributed to this report.