The United States has sanctioned 11 North Koreans and one North Korean coal company for their links to the country's nuclear weapons program.
The US Treasury on Friday accused the individuals of working as agents of North Korea's government in Russia, China, Vietnam and Cuba to provide financial support for previously sanctioned companies.
"Today's sanctions are aimed at disrupting the networks and methods that the Government of North Korea employs to fund its unlawful nuclear, ballistic missile, and proliferation programs," Treasury Secretary Steven Mnuchin said in a statement. "I urge our partners and allies to take similar measures to cut off its funding."
North Korea has launched three failed missile tests this month. In response, Secretary of State Rex Tillerson said that military options could be "on the table" if they continue testing nuclear weapons.