The names will be published in the official journal of the European Union in the coming days.
So far, the EU has imposed limited measures, targeting 61 people in Russia and Ukraine with asset freezes and travel bans, as well as two energy companies in the Ukrainian peninsula of Crimea, seized and annexed by Moscow earlier this year.
Read MoreUkraine ceasefire ends: Why you should worry
EU leaders warned at a June 27 summit that the bloc could mete out more sanctions against Russia unless pro-Moscow separatist forces wound down the crisis in the east of Ukraine within a few days.
They demanded that the rebels agree to ceasefire verification arrangements, return Ukrainian border checkpoints to Kiev authorities, free hostages and launch serious talks on implementing Ukrainian President Petro Poroshenko's peace plan.
"The new names were added because of the non-compliance with the conditions set out by EU leaders in June," the diplomat said.
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Poroshenko decided a week ago to call off a patchy 10-day ceasefire and resume an offensive against the rebels in eastern Ukraine.
The EU has hesitated to impose hard-hitting trade sanctions against Russia because of fears among some member states about antagonising their major energy supplier.
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