Kim Jong Un's mysterious sister, Kim Yo Jong, issued a rare public threat to the US on her brother's behalf, hinting that she might be gaining influence

• Kim Jong Un's sister threatened the US against intercepting North Korean missile tests on Tuesday.
• Kim Yo Jong comments come as the US and South Korea ramp up military and combat drills.
• Ms. Kim's presence in her brother's government is mysterious, but she may be gaining influence.

Kim Jong Un's sister Kim Yo Jong threatened the US on Tuesday against intercepting any North Korean missile tests over the Pacific Ocean, calling any interference a "declaration of war."