Winston Peters says US scaling back of military drill New Zealand involved in 'a surprise'

The Defence Force (NZDF) says it was not given a heads up a joint military training exercise New Zealand is taking part in with allies was being significantly reduced - and found out it was being cut by six days through media reports.

Exercise Ulchi Freedom Shield is an annual training in South Korea led by the permanent United Nations Command (UNC) in the country, which was established in 1950 to give "legal authority for member states to restore peace on the Korean Peninsula".

The exercise was supposed to run from 17-27 August, with an estimated 18,000 troops from at least 12 UNC members.

Twelve New Zealanders were already deployed in established UNC positions and they were bolstered by "seven augmentees" in preparation for the exercise, an NZDF spokesperson said.

The New Zealand contingent were contributing to "the exercise's planning, co-ordination, and delivery".

But as it was getting underway on Monday, US President Donald Trump wrote on his social media page that he was asking his secretary of defence to scale it back.

Trump cited his "very good relationship" with North Korea's leader, Kim Jong-un, and the costs of the 10-day exercise as being behind the decision.

"These exercises are not only costly, with much of these costs paid for by the United States of America (as usual!) [sic], but send a signal that is totally inappropriate and hostile, to a Country [sic] that, as long as Donald J. Trump has been President, has been unthreatening and respectful," he wrote.

In a statement, an NZDF spokesperson said it became aware of the scaling back "shortly after President Trump's announcement".

"NZDF received the same notification about the proposed changes as did other troop-contributing nations," they said.

Foreign Minister Winston Peters said "it was a surprise, I can't deny that".

"We've been there all this time, we have the second highest number of soldiers there," he said.

The NZDF spokesperson said "the exercise remained a UNC-led activity involving permanent and multinational planners".

South Korean media reported the commander of US forces visited the South's Defence Ministry on Tuesday to discuss plans to scale it back - after the exercise had begun.

Then on Wednesday, South Korea's Joint Chiefs of Staff (JCS) and a Pentagon official said Exercise Ulchi Freedom Shield would now end on Friday - six days earlier than originally planned.

In a statement on social media, South Korean President Lee Jae Myung said he recognised Trump's "will and efforts to create conditions for dialogue" with North Korea through the reduction of the exercises.

The NZDF spokesperson said personnel taking part in the exercise weren't told directly about the significant cut, they instead "heard about the Joint Chiefs of Staff statement via media reports".

At the suggestion of the United States, the countries agreed on partial adjustments to the duration and scope of the drills, the JCS said.

Some combined field manoeuvre training would also be scaled back.

A US Department of Defence official said it had substantially reduced the exercise and associated live-training events, with some cancelled or switched to simulations.

The changes would preserve essential readiness and training aims, with no degradation to US training objectives, the official added.

"The NZDF has not yet received enough information from United States authorities to determine what the impact will be on future activities," the spokesperson said.

"New Zealand is a long-standing supporter of peace and stability on the Korean Peninsula. The US and Republic of Korea continue to be very important partners, both for security on the Peninsula and in the wider region," a spokesperson for Winston Peters said.

"New Zealand's deployment to the UN Command reflects our ongoing commitment."

North Korea reacts

North Korea denounced the military drills by the US and South Korea, despite Trump's order to the Pentagon to "substantially reduce" US participation.

North Korean state media reported that Kim Yo Jong, the sister of leader Kim Jong Un, dismissed the move, saying the nature of the exercises remained provocative and aggressive, even if the scale and duration had been reduced.

A day later on Thursday, South Korea and Japan reported that North Korea had fired several short-range ballistic missiles towards the sea off its eastern coast on Thursday.

A Russian foreign ministry spokesperson told reporters Moscow "could only welcome" the US decision to cut back its participation in military exercises with South Korea, while China's foreign minister had urged South Korea not to take sides between Beijing and Washington, saying the US should abandon its "hostile" policy toward North Korea to ease tensions on the Korean Peninsula.

- RNZ with wires