South Korea's foreign minister expressed on Wednesday that US President Donald Trump's ordering the scaling back of joint military drills appeared to include pressure on Seoul to become involved in the war on Iran.

"I think President Trump's message includes pressure over several pending issues concerning the South Korean government, as well as a message to North Korea and an intention by the United States to break a stalemate in the Iran war," Cho Hyun said.

Cho indicated that neither South Korean nor US officials had prior knowledge of Trump’s order to reduce joint military exercises.