Romania's president says he didn't know the prime minister would attend the European Games, which has been boycotted by most European Union leaders due to concerns about Azerbaijan's human rights record.
Prime Minister Victor Ponta was in Baku on June 12 for the opening of the games, together with Russian President Vladimir Putin and Turkish President Recep Tayyip Erdogan.
President Klaus Iohannis called Ponta's attendance "a foreign policy gaffe," and said on June 15 that he had not known about the visit.
Relations have soured between the two leaders after Ponta was named in a corruption probe. Iohannis asked the prime minister to resign and he refused.
On June 5, prosecutors said Ponta was suspected of money laundering, forgery, tax evasion and conflict of interest.
He later survived a no-confidence vote and a bid to lift his immunity failed.