RIGA (REUTERS) - "Hello, dictator!" is an uncommon form of address for a European leader to use to another but EU chief executive Jean-Claude Juncker greeted Hungary's Viktor Orban that way on Friday.

Delivered with a mischievous smile and a warm handshake at a summit in Riga, the European Commission president's remark seemed to mix mild admonishment with heavy humour to try to defuse tension after a particularly rough week in relations between Brussels and the right-wing prime minister in Budapest.

On Tuesday, the European Parliament called a debate in response to suggestions from Hungarian officials that they might revive the death penalty.

Orban, 51, flew in specially to give a typically robust defence, and also used the occasion to denounce Juncker's new plan for helping asylum-seekers as "insanity".

EU officials and diplomats say they have heard Juncker, 60, a veteran former conservative premier of Luxembourg, use the"Hello, dictator" line to Orban on occasions in the past.

But this time it was overheard by news photographers.

Orban appeared characteristically unfazed by the greeting.