United Nations officials who recently visited North Korea say that during their visit they urged Pyongyang to promptly return to the six-way nuclear talks without any preconditions attached.

Secretary-General Ban Ki-moon’s special envoy to the North, Lynn Pascoe, and Ban’s advisor, Kim Won-soo, made the statement to reporters on Wednesday at the U.N. headquarters in New York.

The two officials said they held extensive talks with North Korean officials on ways to improve U.N.-North Korea ties, adding that the talks were useful.

According to the officials, the North voiced hope to improve relations with South Korea but neglected to respond when calls were made for its return to the six-nation talks.

North Korean officials also reportedly expressed strong complaints about U.N. sanctions and resolutions denouncing the North’s human rights situation.

U.N. and North Korean officials did agree, however, that the U.N. Development Program (UNDP) would resume operations this month.