U.S. Ambassador Alexander Vershbow says he found "very helpful" seeing the progress of an inter-Korean industrial complex in the North Korean border city of Gaesong.

In an interview Monday with reporters after visiting the complex along with 76 other foreign envoys, he said the United States has long supported more inter-Korean exchanges and wants to see the barrier between the two Koreas collapse.

Vershbow said he learned many things about the complex and that he will tell his colleagues in Washington about it.

He said he hopes the information he relays will help his colleagues better understand what is happening in Gaesong given lingering questions over the complex.

Foreign Minister Ban Ki-moon, who accompanied the envoys to Gaesong, said the complex is a politically symbolic project in maintaining peace on the Korean Peninsula and in ultimately achieving reunification.