North Korea may have delivered exports of nuclear material UF6 through an international broker and not the Pakistani government.

Outgoing US Ambassador Christopher R. Hill on Wednesday told a discussion at the Civil Network for a Peaceful Korea that Pyongyang already knew the UF6 would arrive in Libya. He said the North used the rouge AQ Khan network to export it there.

He also rejected again Pyongyang's demand for a US apology over calling the North an "outpost of tyranny.