(QHA) -

The United States and European Union have announced sanctions aimed at punishing a handful of Russians and Ukrainians for their roles in destabilizing Ukraine, where a weekend referendum in Crimea endorsed a plan by breakaway officials there to join the Russian Federation, RFE/RL reports.

President Barack Obama announced the imposition of U.S. sanctions against seven Russians and four Ukrainians, including a Russian deputy prime minister, two presidential aides, two pro-Russian Crimean separatist leaders, and ousted Ukrainian President Viktor Yanukovych.

Earlier, the European Union announced travel bans and asset freezes on 21 Russians and Ukrainians.

Lithuania's Foreign Minister Linas Linkevicius said on Twitter that more measures are likely in the coming days.