President Donald Trump on Monday said the U.S. is designating North Korea as a state sponsor of terrorism.

The designation "should have happened a long time ago," the president said at the start of a Cabinet meeting. He cited the regime's nuclear weapons program, acts of international terrorism, and the death of 22-year-old student Otto Warmbier of Cincinnati.

The designation will impose further sanctions and penalties on Kim Jong Un's regime. Trump said the Treasury Department will announce additional sanctions on North Korea on Tuesday.

Secretary of State Rex Tillerson said the sanctions will be similar to past sanctions, but broader. He said the current sanctions on the regime are having an effect on the country's revenues and fuel supply.

"This is a process that started actually several months ago," Tillerson said during a press briefing Monday at the White House.

The move returns North Korea to the list of countries the U.S. views as state sponsors of terror for the first time since 2008. That's when the North was removed in a bid to salvage a deal to halt its nuclear development.

U.S. officials cited the killing of Kim's estranged half brother Kim Jong Nam in a Malaysian airport this year as an act of terrorism.

"The assassination in Malaysia was a significant event," Tillerson told reporters Monday.

Warmbier died after being returned to the United States from North Korea in an unconscious state. He had been sentenced to 15 years in prison with hard labor after confessing to attempting to steal a banner while visiting North Korea.

North Korea joins Iran, Sudan and Syria on the U.S. list of state sponsors of terror.

Reuters and The Associated Press contributed to this report.