US President Donald Trump delivered an address to the nation Wednesday following Iranian missile attacks on US forces in Iraq.

"As long as I'm president of the United States, Iran will never be allowed to have a nuclear weapon," Trump declared at the start of his speech.

The president said that Americans should be "happy" and "grateful" following the killing of Iranian General Qassem Solemaini.

“All of our soldiers are safe,” he said, noting that there were no American casualties in the the ballistic missile attacks launched by Iran against US forces in Iraq overnight.

“Iran appears to be standing down," he added.

Trump accused Iran of being the world's leading state sponsor of terrorism and noted that the Islamic Republic's "pursuit of nuclear weapons threatens the civilized world."

"For far too long, all the way back to 1979 to be exact, nations have tolerated Iran's destructive and destabilizing behavior in the Middle East and beyond. Those days are over," Trump said.

The president called Solemaini “the world’s top terrorist."

"Last week we took decisive action to stop a ruthless terrorist from threatening American lives," he said. "As head of the Quds Force, Solemaini was personally responsible for some of the absolutely worst atrocities. He trained terrorist armies, including Hezbollah, launching terrorist strikes at civilian targets. He fueled bloody civil wars all across the region. He viciously wounded and murdered thousands of US troops including the planting of roadside bombs that main and dismember their victims."

"Solemaini's hands were drenched in both American and Iranian blood. He should have been terminated long ago," Trump declared. "By removing Soleimani, we have sent a powerful message to terrorists: If you value your own life, you will not threaten the lives of our people.

Trump went on to announce new sanctions against Iran. "As we continue to evaluate options in response to Iranian aggression, the United States will immediately impose additional punishing economic sanctions on the Iranian regime. These powerful sanctions will remain until Iran changes its behavior. "

"In recent months alone, Iran has seized ships in international waters, fired an unprovoked strike on Saudi Arabia, and shot down two U.S. drones.

He blamed the 2015 nuclear deal for the increase in Iran's aggression across the Middle East. "Iran’s hostilities substantially increased after the foolish Iran nuclear deal was signed in 2013, and they were given $150 billion, not to mention $1.8 billion in cash. Instead of saying "thank you" to the United States, they chanted "death to America." In fact, they chanted "death to America" the day the agreement was signed. "

"Then, Iran went on a terror spree, funded by the money from the deal, and created hell in Yemen, Syria, Lebanon, Afghanistan, and Iraq. The missiles fired last night at us and our allies were paid for with the funds made available by the last administration. The regime also greatly tightened the reins on their own country, even recently killing 1,500 people at the many protests that are taking place all throughout Iran.

Trump called on the signatories to the nuclear deal to stop propping up the agreement and confront Iran's threats to world peace. "The very defective JCPOA expires shortly anyway, and gives Iran a clear and quick path to nuclear breakout. Iran must abandon its nuclear ambitions and end its support for terrorism. The time has come for the United Kingdom, Germany, France, Russia, and China to recognize this reality."

"They must now break away from the remnants of the Iran deal -– or JCPOA –- and we must all work together toward making a deal with Iran that makes the world a safer and more peaceful place. We must also make a deal that allows Iran to thrive and prosper, and take advantage of its enormous untapped potential. Iran can be a great country.

"Peace and stability cannot prevail in the Middle East as long as Iran continues to foment violence, unrest, hatred, and war. The civilized world must send a clear and unified message to the Iranian regime: Your campaign of terror, murder, mayhem will not be tolerated any longer. It will not be allowed to go forward."