President Trump warned that Iran’s supreme leader Ayatollah Ali Khamenei should be “very worried” during an interview on Wednesday amid rising tensions between Washington and Tehran.

“I would say he should be very worried, yeah. He should be,” Trump told anchor Tom Llamas on NBC Nightly News.

Tensions between the U.S. and Iran have intensified in recent weeks amid the regime’s iron-fisted approach to silence protesters. Trump affirmed on Wednesday that the U.S. still supports the country’s protesters.

“We have had their back. And look, that country’s a mess right now because of us,” he said. “We went in, we wiped out their nuclear,” the president said, referring to the U.S. operation that attacked three nuclear facilities in the country, known as “Operation Midnight Hammer.”

“If I didn’t take out their nuclear, think of it, if we didn’t take out that nuclear, we wouldn’t have peace in the Middle East because the Arab countries could have never done that,” he added.

“They were very, very afraid of Iran,” he continued. “They’re not afraid of Iran anymore. We wiped out those beautiful B-2 bombers, ones right over there, those beautiful little models.”

Trump also claimed that the U.S. had heard Iran was seeking to restart the program.

“They tried to go back to the site. They weren’t even able to get near it. There was total obliteration. But they were thinking about starting a new site in a different part of the country,” he said. “We found out about it. I said, you do that, ‘We’re going to do very bad things to you.’”

The U.S. has established a substantial military presence near Iran recently, which was boosted with the arrival of the USS Abraham Lincoln and its strike group in the U.S. Central Command (Centcom) area, along with the arrival of additional fighter jets and cargo planes to the region.

Officials from both countries are slated to meet in Oman on Friday to discuss Iran’s nuclear program.

On Tuesday, White House press secretary Karoline Leavitt confirmed that U.S. forces shot down an Iranian drone after it “aggressively approached” the aircraft carrier USS Abraham Lincoln

The president has warned on numerous occasions that he could authorize strikes on the country if negotiations fall apart.