Kim Jong Un makes nuclear pledge after South Korea-US military drills
South Korea begins removing propaganda speakers from border with North
North Korean leader Kim Jong Un condemned the joint US-South Korean military drills, labelling them an "obvious expression of their will to provoke war".
Mr Kim vowed to rapidly expand North Korea's nuclear arsenal and inspected an advanced warship being fitted with nuclear-capable systems.
Seoul and Washington maintain the exercises are purely defensive, despite Pyongyang regularly criticising them as rehearsals for invasion.
Efforts to address North Korea's nuclear weapons development are expected to be discussed at an upcoming meeting between Donald Trump and South Korean president Lee.