Senior U.S. diplomat Wendy Sherman says that the U.S. has had direct contact with North Korea.
Sherman disclosed the information during her virtual keynote address to the Korea Society's annual dinner in New York on Tuesday local time.
She added that the U.S. State Department made specific proposals to the regime and has been waiting for a response.
Meanwhile, South Korean nuclear envoy Noh Kyu-duk said the end-of-war declaration is being discussed in a "serious manner."
He told reporters on Wednesday after returning from his visit to Washington to meet with American counterpart Sung Kim to discuss North Korea issues.
He said he is looking forward to Sung Kim visiting Seoul to further discuss the matter this weekend.