North Korea said it will never negotiate its sovereignty with the United States, criticizing Washington as "double-faced" for offering talks while ramping up military activities in the region, state media KCNA reported on Thursday.

Kim Yo Jong, the powerful sister of North Korean leader Kim Jong Un and a senior official, said the U.S. showed "extreme double standards" at this week's meeting of the U.N. Security Council over North Korea's recent launch of its first spy satellite.

The meeting set the stage for a rare, public spat between U.S. Ambassador Linda Thomas-Greenfield and North Korean Ambassador Kim Song, both arguing that their countries' military activities are defensive.