Tribunal officials have sent a letter to former king Norodom Sihanouk, the first correspondence through official channels following the monarch's invitation for talks.
It was unclear if the letter was an official decline to an open invitation to the Palace Sept. 8, but UN tribunal spokesman Peter Foster told the Cambodia Daily Thursday he had no authority to take part in discussions outside the purview of the court.
Controversy has surrounded the former king lately as to whether he is immune to tribunal proceedings seeking to prosecute former leaders of the regime.
Sihanouk sat at the head of a coalition that included the Cambodian communists prior to their takeover of the country in 1975. He has not been summoned to the courts—as defense or witness.
A palace official said Thursday the tribunal members should be honored by the invitation of the former king, a national "hero."