European Council President Antonio Costa at a press conference in Brussels, Belgium. (Photo: Xinhua/VNA)

Diplomats and officials told Politico that Costa raised the issue directly with EU leaders during visits to several European capitals and in bilateral meetings on the sidelines of the United Nations General Assembly in New York last week.

Politico also reported that EU enlargement commissioner Marta Kos travelled to Ukraine on Monday, as Ukraine completes the screening of legislation required to move forward with its candidacy.