The U.S. announced Friday it is sanctioning North Korean digital currency mixing firm Blender.io, which the country allegedly uses to launder stolen virtual currency and support cyber crimes.

The sanctions, imposed by the Treasury Department’s Office of Foreign Assets Control, are the first ever on a digital asset mixing service. The new sanctions also point to the growing use of digital assets to perpetuate illegal acts by state actors and individuals.

Mixing services combine various assets, including potentially illegally obtained funds and legitimately obtained funds, so that illegal actors can obscure the origin of stolen funds.

Blender is accused of helping Lazarus Group, a sanctioned North Korean cyber hacking group, to carry out a $620 million digital currency heist in March, the biggest of its kind to date.

Treasury says Blender helped process over $20.5 million in digital currency. Lazarus Group was designated in September 2019 as a state-sponsored cyber criminal group.

Four wallets, or virtual currency addresses, tied to Lazarus Group were also added to Treasury's list of sanctioned entities.

“The United States remains committed to seeking diplomacy with the DPRK and calls on the DPRK to engage in dialogue,” Secretary of State Antony Blinken said in statement. “At the same time, we will continue to address the DPRK’s unlawful cyber activities, as well as violations of U.N. Security Council resolutions.”

DPRK is an acronym for the country’s formal name, the Democratic People’s Republic of North Korea.

Under Secretary of the Treasury for Terrorism and Financial Intelligence Brian Nelson said virtual currency mixers that assist illicit transactions “pose a threat to U.S. national security interests.”

“We are taking action against illicit financial activity by the DPRK and will not allow state-sponsored thievery and its money-laundering enablers to go unanswered," he said.

Last month, the U.S. imposed its first set of penalties against a cryptocurrency mining firm in relation to Russia's war on war. Digital currency firm Bitriver AG and 10 of its subsidiaries were included in a package of sanctions from Treasury’s Office of Foreign Assets Control.

Lawmakers and administration officials have voiced concerns about the use of cryptocurrency to engage in illicit acts.