BRUSSELS, Feb 23 (Reuters) - European Council President Antonio Costa on Monday urged Hungarian Prime Minister Viktor Orban to honour an EU deal for a 90 billion euro ($106.11 billion) loan to Ukraine, after Budapest said it would block the plan until Russian oil flows again through the Druzhba pipeline that traverses Ukraine.
"When leaders reach a consensus, they are bound by their decision. Any breach of this commitment constitutes a violationof the principle of sincere cooperation," Costa, who chairs summits of EU leaders, said in a letter to Orban seen by Reuters.
"No Member State can be allowed to undermine the credibility of decisions taken collectively by the European Council," Costa wrote, referring to the loan, which was approved by EU leaders at a summit in December.
($1 = 0.8482 euros)
(Reporting by Andrew Gray, editing by Inti Landauro)
