US President Donald Trump has instructed the Pentagon to substantially reduce joint military exercises with South Korea, citing their cost and Seoul’s refusal to participate in US actions against Iran.

Trump said the drills send an inappropriate and hostile signal to North Korea, while highlighting his “very good relationship” with its leader, Kim Jong Un.

South Korea said the exercises began as scheduled and that it will continue coordinating with the US on defence, while reviewing Trump’s comments and seeking dialogue to promote peace on the Korean Peninsula.