The Prime Minister of New Zealand has described Donald Trump's recent threats against Iranian civilian infrastructure as "useless".

Afghan Voice Agency (AVA): Christopher Lacson told Radio New Zealand about Trump's threats: "(These threats) are useless because further military action is not necessary."

He added: "I think the main point is that the focus should be on preventing the conflict from escalating further. Any of these actions, including bombing bridges and tanks and civilian infrastructure, would also be unacceptable."

Lacson said the message from New Zealand Foreign Minister Winston Peters to US Secretary of State Marco Rubio at a meeting in Washington - scheduled for this week - would be to "quickly" de-escalate the conflict.