A visit by a U.S. aircraft carrier to South Korea prompted a warning from the sister of North Korea’s leader that Washington and Seoul “should not test” the communist regime.

The U.S. aircraft carrier USS Carl Vinson arrived at the southern port city of Busan in South Korea on Sunday as a show of force against North Korea, South Korea's navy said.It is the first U.S. aircraft carrier to dock at a South Korean port since U.

The arrival of the carrier Carl Vinson and its strike group at the South Korean port of Busan was meant to display a solid U.S-South Korean military alliance in the face of persistent North Korean threats, and boost interoperability of the allies’ combined assets, the South Korean navy said in a statement.