After two referendums held on Sunday in parts of eastern Ukraine, the European Union has added 13 people and two businesses to its visa ban and asset freeze list, officials said Monday.

This is the first time enterprises have been included in the sanctions list, which now has a total of 61 people listed. The latest additions were confirmed by two officials who spoke on condition of anonymity because the measure had yet to be officially announced, the Associated Press reports.

The EU’s initial sanctions list included 48 people. While Russian businesses with ties to Moscow's annexation of Ukraine's Crimea region have been included in the U.S. sanctions list, the EU only authorized a similar measure for its list last week.

Foreign ministers met in Brussels today to discuss the extended sanctions against Russia. The move is meant to raise pressure on Russia to avoid it interfering with the May 25 Ukrainian presidential election.

"We need to send a clear message that what we have seen until now is completely unacceptable," Dutch Foreign Minister Frans Timmermans told reporters.

For now, the new names of individuals and businesses on the EU list are subject to travel bans and will have their assets frozen. The names have been limited to firms or other organizations that “obstruct international organizations in the completion of their tasks" or "support the Russian government in the completion of its tasks." The EU has not targeted high-profile firms such as Gazprom.

British Foreign Secretary William Hague said the EU is prepared to intensify economic sanctions "if the circumstances require it, particularly determined by the Russian attitude to the elections on May 25."

German Foreign Minister Frank-Walter Steinmeier said he would travel to Kiev on Tuesday to open a dialogue between eastern and southern Ukraine, adding that Russia’s involvement in the upcoming Ukrainian presidential election will determine whether further actions need to be taken.

"We have to be prepared for what to do if someone prevents the elections on May 25. It that is going to happen ... then we have to think about further sanctions," he said.