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".

He described enlargement as having "unprecedented efficiency and stabilizing power". Ukraine is currently committed to signing only an Association Agreement on March 21, as European Foreign Ministers decided on Monday's emergency meeting in Brussels.

Association Agreement with Ukraine will be signed after the EU has implemented for years its European Neighborhood Policy, which was openly designated for countries with slim prospects or no prospects at all to join the union.

Die Welt, however, quotes Fule as explicitly saying accepting Ukraine into the EU could only be a "long-term" goal.

He reminded that EU leaders had already agreed that an agreement with Kiev and the unilateral drop of trade barriers will not be the final point in the relations of both sides.

It was precisely the refusal to sign of an EU Association Agreement that triggered protests and violence across Ukraine's ousted president Viktor Yanukovych in mid-November 2013 and led to him fleeing the country after Parliament declared him "illegitimate" on February 22 this year.