EU countries' leaders are due to decide in mid-December on whether to accept the Commission's recommendation to invite Kyiv to begin membership talks as soon as it meets final conditions.

Any such decision requires unanimity of the bloc's 27 members, with Hungary seen as the main potential obstacle.

Nationalist Orban, in power since 2010, said a dispute between Brussels over billions of euros of EU funds suspended for Hungary over a rule-of-law issue cannot be linked in any way to Hungary's support for Ukraine's EU accession talks.

"Membership talks must not be started, this is the clear Hungarian stance," Orban said, adding that Brussels "owed Hungary money."

"I would like to make it very clear that the Hungarian rejection of the start of talks with Ukraine over EU membership is not subject to a business deal ...It cannot be linked to the issue of funds that Hungary is entitled to get."

Orban is faced with economic stagnation this year and a widening budget deficit as the country clambers out of Europe's highest inflation rates that peaked above 25% in the first quarter. Investors have been eyeing Budapest's talks with Brussels over the EU funds very closely.

Orban has had many bitter run-ins with the EU and its executive arm, the European Commission, over Budapest tightening state controls over non-governmental organizations, academics, media and courts, as well as a law that is seen hurting LGBT rights.