The Foreign Affairs Minister has rebuked Reserve Bank Governor Dr Anna Breman for signing a statement expressing “full solidarity” with US Federal Reserve chairman Jerome Powell after the US Justice Department launched an investigation into him.

In a social media post on Wednesday afternoon, Winston Peters said the Reserve Bank was “statutorily independent” of the central Government on monetary policy but has “no role, nor should it involve itself in US domestic politics”.

“We remind the Governor to stay in her New Zealand lane and stick to domestic monetary policy. That would have been the advice of the Ministry of Foreign Affairs and Trade if the Governor had sought its advice, which she did not.”

The Herald has contacted the Reserve Bank for reaction. Finance Minister Nicola Willis’ office would not comment when approached.

In a statement issued this week, several heads of central banks said they stood “in full solidarity with the Federal Reserve system and its chair Jerome H. Powell”.

“The independence of central banks is a cornerstone of price, financial and economic stability in the interest of the citizens that we serve,” they said.

“It is therefore critical to preserve that independence, with full respect for the rule of law and democratic accountability.

“Chair Powell has served with integrity, focused on his mandate and an unwavering commitment to the public interest. To us, he is a respected colleague who is held in the highest regard by all who have worked with him.”

Among those who signed the letter are Christine Lagarde, president of the European Central Bank, Bank of England Governor Andrew Bailey, Michele Bullock of the Reserve Bank of Australia and Breman.

It comes after the US Justice Department launched a probe into Powell relating to the renovation of Federal Reserve office buildings.

Jerome Powell says the investigation is because of the Federal Reserve setting interest rates independently and not in response to US President Donald Trump's wishes. Photo / Saul Loeb

Powell has said the threat of criminal charges were a consequence of the Federal Reserve setting interest rates “based on our best assessment of what will serve the public, rather than following the preferences of the President”.

“This unprecedented action should be seen in the broader context of the administration’s threats and ongoing pressure.”

US President Donald Trump on Wednesday said Powell was a “jerk” and a “lousy Fed chairman”. The investigation has been viewed by some in the US as retaliation for the Federal Reserve not bringing interest rates down as quickly as the President wished, though Trump has denied any connection to the probe.

A Reserve Bank spokesperson was reported by RNZ as saying earlier on Wednesday that Breman believed strongly in the independence of central banks.

“Dr Breman’s signature on the statement indicates the support of the Reserve Bank of New Zealand, which is statutorily independent from the New Zealand Government,” they said.

Jamie Ensor is the NZ Herald’s Chief Political Reporter, based in the Press Gallery at Parliament. He was previously a TV reporter and digital producer in the Newshub Press Gallery office. He was a finalist in 2025 for Political Journalist of the Year at the Voyager Media Awards.