Veto is not an instrument in the dialogue between leaders of the European Council, Bulgaria's Prime Minister said.
Plamen Oresharski made this comment on Tuesday, shedding some light on his future stance toward the prospect of introducing European-level measures against Russia, the website Dnevnik.bg has reported.
The EU has imposed sanctions on another 12 individuals over Russia's annexation of Crimea from Ukraine, but failed to agree on economic sanctions.
With this the total number of persons on the sanctions list reached 33.
Meanwhile, the EU leaders warned that further economic sanctions can be imposed on Russia, if the situation in Ukraine deteriorates.
Armed Russian forces arresting Ukrainian army officers during an operation in Simferopol on Tuesday.
Greeces prime minister and foreign minister walked a careful line on Tuesday between backing the European Unions position on Crimea but also insisting that attempts should continue at reaching a diplomatic compromise with Russia over the Ukrainian region.
EU is 'obliged' to use enlargement in its policy toward Ukraine, Commissioner Stefan Fule said on Tuesday.
Speaking for German newspaper Die Welt, Fule, who is in charge precisely of the EU's enlargement policy, said the bloc should use "its strongest instrument" if it wants to deal with "this part of Eastern Europe which last events have affected".
The political part of EU's Association Agreement in Ukraine will probably be signed next week.
After Wednesday's talks with German Chancellor Angela Merkel, Polish Prime Minister Donald Tusk announced that, "if there are no technical obstacles", signing of some documents regarding the agreement should take place at the upcoming meeting of the European Council, which is next week.