The North Korean leader’s powerful sister denounced a stopover by a U.S. nuclear-powered submarine in South Korea as a “frantic” attempt to demonstrate American military strength, claiming that a DPRK spy satellite detected the vessel’s arrival.

In a statement released Tuesday night, Kim Yo Jong asserted that the Aerospace Reconnaissance Agency detected “an abnormal object at a wharf” in the port city of Busan on Monday morning, in an apparent attempt to demonstrate the country’s improved reconnaissance capabilities since putting the satellite in orbit last year.

“This clearly reveals the frantic military and strategic attempt of the U.S. hell-bent on