The US Treasury listed eight separatist officials and the Eurasian Youth Union, a nationalist Russian group said to recruit fighters to join the rebels, under the sanctions.
The separatists include Aleksandr Karaman, Oleksandr Khodakovsky, and Ekaterina Gubareva, top officials with the self-proclaimed rebel Donetsk People's Republic in Ukraine.
The Treasury named as well the Russian National Commercial Bank, a formerly little-known institution which has become the largest bank in Crimea since Russia seized the region from Ukraine one year ago.
The sanctions freeze any assets of the individuals and institutions held on US property and ban Americans from doing business with them.
For Russian National Commercial Bank, the sanctions effectively lock it out of major parts of the global financial system by forbidding other banks with US presences -- including most large global banks -- from handling money for it.
The Treasury called the sanctions "part of an ongoing effort to hold accountable those responsible for violations of Ukraine's sovereignty and territorial integrity."
"If Russia continues to support destabilizing activity in Ukraine and violate the Minsk agreements and implementation plan, the already substantial costs it faces will continue to rise," he said.
