"We have given time and taken measures to build trust but there have been no corresponding measures in return. The only thing we have received was a sense of betrayal," she added.

Her remarks come as Pyongyang has been ramping up demand for Washington to drop its hostile policy and come up with an acceptable proposal before the end of this year, a Pyongyang-imposed deadline.

Denuclearization talks have been stalled since the second summit between North Korean leader Kim Jong-un and US President Donald Trump in February broke down as they failed to find common ground over how to compensate Pyongyang's denuclearization.

The two sides resumed working-level talks in Sweden early last month but failed again to produce any tangible results.

Earlier this week, South Korea and the US announced the postponement of their planned combined military exercises as an "act of goodwill" aimed at bolstering diplomacy over North Korea.

On Wednesday, Choe, who is considered leader Kim's key nuclear strategist, reiterated Pyongyang's position, saying that denuclearization can be discussed again only when the US drops all hostile policies against the North. (Yonhap)