Propaganda loudspeakers aimed at South Korea will be ready to restart within days along the entire border, Kim Yo-jong, the powerful sister of North Korean leader Kim Jong-un, has said amid a worsening of ties between the two countries.

The statement, carried by the state news agency KCNA on Thursday, came a day after she said the loudspeakers would be in operation along the whole border from some time in October.

Both North and South Korea have historically used giant loudspeakers to broadcast propaganda across the border, with the North in recent years playing haunting bestial howls, and the South opting for K-pop music ​and news criticising Pyongyang.

If the broadcasts resume, they would be the first loudspeaker exchange across the border in 16 months.…