Trump scales back joint military drills with South Korea, calling them 'hostile'

US President Donald Trump has ordered the Pentagon to scale back planned joint military exercises with South Korea, saying the nation had declined to help denuclearise Iran.

He said the exercises slated to begin this week were costly and sent a "totally inappropriate and hostile" signal to North Korea.

South Korea's defence ministry said the exercises would proceed as scheduled.

US President Donald Trump has ordered the Pentagon to scale back planned joint military exercises with South Korea, saying it declined to help denuclearise Iran and citing his good relationship with North Korean leader Kim Jong Un.

Mr Trump said in a social media post on Sunday, local time, that the exercises slated to begin this week were costly and sent a "totally inappropriate and hostile" signal to North Korea, which he said had been "unthreatening and respectful" while he had been in the White House.

"Therefore, and based on the fact that it is too late to cancel, I have instructed Secretary of War, Pete Hegseth, to substantially reduce the Joint Military Exercises!" Mr Trump wrote.

Mr Trump added that he recently asked South Korea's president to join the US in its efforts to denuclearise Iran, "and they said, 'No thanks!'"

When asked about the post, South Korea's defence ministry said the exercises would proceed as scheduled.

"We will proceed as previously notified and scheduled," a ministry spokesperson said in a brief statement.

The 11-day exercises, involving 18,000 South Korean soldiers, were designed to boost readiness against North Korean threats.

North Korea on Friday threatened unspecified stern steps against the US and South Korea, describing their military drills as "a rehearsal for an aggressive war" and accusing them of triggering greater instability in the region.

The warning was typical of the harsh rhetoric North Korea often deploys ahead of major US-South Korean military exercises.

Experts say North Korea has often used its rivals' drills as a pretext to ramp up testing activities to expand its weapons arsenals and promote public support for the reclusive North Korean leader.

US and South Korean forces were expected to practise joint operations in complex scenarios, including a live-fire exercise to test joint precision targeting and manoeuvring, a wet gap crossing, and distribution of pre-positioned military equipment, according to the US military.