European Union leaders will hold an emergency summit on Thursday to discuss the way forward on Russia's recognition of Donetsk and Luhansk after the bloc approved a first, limited round of sanctions on Wednesday, Reuters reported.

The EU sanctions, which came into force on Wednesday, include the blacklisting of numerous politicians and a ban on trade between the EU and Donetsk, Luhansk.

"It is important that we continue to be united and determined and jointly define our collective approach and actions," EU Council chief Charles Michel said in a letter inviting EU leaders to Brussels.

He said a special meeting of the European Council would be held on Thursday from 7 pm.

Michel said the agenda of the meeting would include discussing "how we protect the rules-based international order; how we deal with Russia notably holding Russia accountable for its actions; how we will further support Ukraine and its people."

The impact of the first round of sanctions is likely to be limited, as Western governments have so far preferred to hold in reserve the much larger packages of sanctions they have planned in case the crisis escalates.