Jean-Claude Juncker, the former president of the European Commission, slammed the idea of Ukraine joining the European Union, saying the country must root out the corruption that touches “all levels” of its society.

Juncker, who presided over the European Commission, a governing body within the E.U., from 2014 to 2019, told German outlet Augsburger Allgemeine that he was upset with some “voices in Europe” conveying to Ukraine that they could join the E.U. immediately. Juncker, who was also the prime minister of Luxembourg from 1995 to 2013, added that Ukraine is not ready to be admitted into the E.U., POLITICO reported.

“Anyone who has had anything to do with Ukraine knows that this is a country that is corrupt at all levels of society. Despite its efforts, it is not ready for accession; it needs massive internal reform processes,” the former European Commission president said.

“You shouldn’t make false promises to the people in Ukraine who are up to their necks in suffering,” Juncker added. “I am very angry about some voices in Europe who are telling Ukrainians that they can become members immediately.”