The United States hit 21 people and nine companies linked to the Russia-backed conflict in eastern Ukraine with new economic sanctions, the latest effort by Washington to put pressure on groups most actively involved in the nearly 4-year-old conflict.

The measures announced on January 26 by the Treasury Department came on the same day that U.S. Secretary of State Rex Tillerson met with Ukrainian President Petro Poroshenko in Davos, Switzerland.

They also came as the U.S. special envoy for the Ukrainian conflict, Kurt Volker, met with his Kremlin counterpart, Vladislav Surkov, to discuss ways to resolve the fighting, Radio Free Europe/Radio Liberty reports.

Since Russia’s 2014 annexation of Ukraine’s Crimea peninsula and the outbreak of fighting in eastern Ukraine, the United States and the European Union have imposed asset freezes, travel bans, and related financial restrictions on a number of Russian people and companies, as well as separatist leaders in the region.