Switzerland said Tuesday it had added 26 more Russian officials and pro-Moscow separatists as well as 18 entities to a blacklist of those considered the main movers in the Ukraine crisis.
The action by Switzerland, which is not an EU member, comes after Germany last week called for broader cooperation in efforts to pressure Russia to halt its support for the separatists.
The total number of individuals on the Swiss list now stands at 88.
Among those added was Alexander Borodai, the "prime minister" of the self-proclaimed People's Republic of Donetsk, the main separatist bastion in eastern Ukraine.
Others included the Donetsk rebels' de facto ministers of security and information.
Also targeted were officials from the so-called People's Republic of Lugansk, another rebel hub.
Among the names from Russia itself were top intelligence and security officials Mikhail Fradkov, Alexander Bortnikov and Boris Gryzlov.
The list also included Ramzan Kadyrov, the controversial leader of Chechnya, who has vowed to send tens of thousand of fighters to back the rebels.
Entities added to the list included the rebel governments and armed forces, and a string of firms seized by the new rulers of Crimea, the strategic Ukrainian peninsula that was annexed by Russia in March.
Unlike the European Union and the United States, Switzerland has been wary of imposing broad sanctions against Russia over Ukraine.
It has instead opted for targeted moves against individuals and firms, and imposed measures to ensure that the Swiss financial sector is not used to duck sanctions introduced by other countries.
The government has argued that it not just a matter of preserving the country's traditional neutrality, but also because Switzerland currently chairs the Organisation for Security and Cooperation in Europe and as such is trying to broker a settlement for the crisis.
People on the Swiss list cannot enter into new business dealings in Switzerland, or with financial intermediaries based in the wealthy nation.
Existing business relationships involving the individuals are not subject to the ban, but must be notified to the government.