European Union leaders will not be able to agree on a ban on Russian oil imports at the Brussels summit, they said upon arrival, adding that weeks of talks on the issue had not yet ended, Reuters reported.

Estonian Prime Minister Kaja Kallas said it was more realistic to expect an agreement next month. 

The next EU leaders' summit is scheduled for June 23-24.

Belgian Prime Minister Alexander de Croo said these are not easy decisions.

Since Hungary is the main opponent of the ban on Russian oil imports, its Prime Minister Viktor Orban said, arriving at the EU summit, that things are not going well with the oil embargo.