Tehran, May 19 (IANS) An Iranian nuclear negotiator said that Tehran seeks a "good" deal with the world powers over its nuclear programme, stressing, however, that the country will **t yield to any "excessive demands by the opposite side", media reported on Tuesday. "We are after a good agreement, but will under ** circumstance give in to excessive demands by the opposite side," Press TV quoted Deputy Foreign Minister Majid Takht-e-Ravanchi as saying on Monday. Iran and the P5+1 group of countries -- the US, Britain, China, Russia, France plus Germany -- are seeking to finalise a comprehensive deal on Tehran's nuclear programme by the end of June.