 -- The Trump administration is updating its sanctions list to include two senior North Korean officials involved in the country's illicit ballistic missile program.

The announcement comes as top White House officials have warned that the U.S. is running out of time to solve the crisis over the regime's nuclear missile capability through its "peaceful pressure" campaign.

Both North Korean officials were added to the United Nations' list last Friday, with the latest round of sanctions that passed the Security Council by a 15-0 vote. North Korean allies China and Russia joined the U.S. for the third time this year in passing even more stringent measures to punish Kim Jong Un over his pursuit of nuclear weapons.

Kim Jong Sik and Ri Pyong Chol are leading officials in the regime's Munitions Industry Department, the government agency responsible for ballistic missile development and heavily sanctioned already by the United Nations and the United States.

"Treasury is targeting leaders of North Korea's ballistic missile program, as part of our maximum pressure campaign to isolate the DPRK and achieve a fully denuclearized Korean Peninsula," Treasury Secretary Steven Mnuchin said in a statement along with the announcement.

But the clock is ticking on that campaign, as North Korea marches onward toward a nuclear-tipped intercontinental ballistic missile potentially capable of reaching the entire United States. The missile most recently tested -- the Hwasong-15 intercontinental ballistic missile, fired on Nov. 28 -- is said to be able to reach the whole continental U.S.

That launch came despite months of increasing pressure, especially at the U.N. with China and Russia's backing.

"President [Donald] Trump has used just about every lever you can use, short of starving the people of North Korea to death, to change their behavior, and so we don't have a lot of room left here to apply pressure to change their behavior," White House Homeland Security Adviser Thomas Bossert told reporters on Dec. 19.

Despite Bossert's warning, the State Department has said it is moving forward in the hopes of doing just that and eventually convincing Kim to come to the table for denuclearization talks.

"Regardless of what others in the U.S. government say, we're pushing ahead with peaceful diplomacy, maximum pressure," State Department spokesperson Heather Nauert said on Dec. 19.

The latest U.N. sanctions will sharply reduce North Korea's oil imports, force the expulsion of all North Korean workers employed overseas within 24 months, and crack down on ships smuggling embargoed material like coal to and from the country.

U.S. ambassador to the U.N. Nikki Haley praised the Security Council for passing the resolution and condemned the regime as "the most tragic example of evil in the modern world," adding, "Should the North Korean regime conduct another nuclear or ballistic missile test, this resolution commits the Security Council to take even further action."