Key aides from Putin's inner circle targeted in new round of EU sanctions

Editor's note: Nina dos Santos is CNN news anchor and correspondent based in London. Follow Nina on Twitter for the latest updates on business.

(CNN) -- European Union leaders agreed to earmark 12 more individuals for visa restrictions and asset freezes in the second stage of their four-step plan to prompt Russia to renege on its annexation of Crimea.

The list, which brings the total number of those targeted to 33, puts the Union on a position closer to the United States. The U.S. also added to its tally of targets on Thursday, tightening the noose around President Vladimir Putin's inner circle.

Nina Dos Santos

Two EU officials confirmed exclusively to CNN that the Speaker of Russia's Upper House, Valentina Matryienko, was among those set to be slapped with sanctions, as was the Deputy Prime Minister Dmirty Rogozin.

Other names among the new additions included two key aides to Putin, Sergey Glazyev and Vladislav Surkov, as well as Dmitry Kisilev, a TV anchor known for his provocative views.

EU members agreed unanimously on the candidacy of some the figures put forward after several hours around the negotiating table at a working dinner which ended after midnight on Thursday.

But some of bloc's 28 states expressed reservations on the names put forward for fear of Russian retaliation, the aides said.

Rogozin, in particular, the official said, was almost blocked by Cyprus and Slovakia, with the latter securing the right to allow him access to its country for meetings of an energy cooperation forum he chairs, one of the officials said.

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Malta also expressed concern about an unnamed candidate for sanctions, but withdrew its objection.

CNN also understands that family members - considered key to the efficacy of any measures- were not explicitly mentioned amid questions about the legality of such a move and the viability of placing travel bans on individuals, who in some occasions are already resident inside the EU.

And for those expecting swathes of Russian industry to feel the brunt of Europe's indignation, there may be disappointment. Despite the US's move to penalise Bank Rossiya, chief executives of the country's largest companies, like Gazprom, Rosneft and VTB Bank, will not feature on the EU's additional file.

What's more: Mr Putin's Chief of Staff Sergey Ivanov and his Minister of Defense Sergey Shoigu -- already frozen out by America -- were left off Europe's list for fear of sending a bellicose signal to Russia.

With many, disparate nations to consider, including some post-Soviet states, the EU has the tough job of balancing competing interests whilst ensuring no one single state will suffer disproportionately from the fallout its sanctions will bring.

This week's steps form part of a four stage process, which will also see Europe punish Russia's financial sector, its energy industry, trade, and its arms business, should the country not respond, people familiar with the discussions confirmed.