BRUSSELS, March 22 (Xinhua) -- Following a time-consuming dinner discussion, leaders of the European Union (EU) on Thursday gave credence to Britain's allegation that "highly likely" Russia is responsible for poisoning a former spy in British soil.

"EUCO (European Council) agrees with UK government that highly likely Russia is responsible for #SalisburyAttack and that there is no other plausible explanation," tweeted European Council President Donald Tusk on Thursday evening.

Russia has denied any involvement in the incident.