Prime Minister Jacinda Ardern has condemned the "devastating" killing of British MP Sir David Amess.
The 69-year-old married father-of-five was stabbed to death on Friday [UK time] while meeting constituents in a church in Leigh-on-Sea in Essex.
A 25-year-old British national, believed to be of Somali heritage, is being questioned on suspicion of murder after being arrested at the scene.
"I send New Zealand's thoughts to the family, friends and constituents of Sir David Amess MP", Ardern said in a statement following the Conservative MP's death.
"No matter where you are in the world, those who represent their communities in parliament should be safe. To hear that someone has lost their life while serving their people is devastating."
New Zealand sent "both our love to Sir David's family, and our condemnation for this act of violence", she said.
Opposition leader Judith Collins described Amess' death as a "sad day for democracy".
"Shocking, and deeply sad news of the murder of Sir David Amess MP, while serving his constituency", Collins tweeted this morning.
"@NZNationalParty and I send our sincere condolences to Sir David's family, friends, colleagues, & constituents. A sad day for democracy."
Amess had been an MP since 1983. He's the second serving British MP to be killed in the past five years, following the murder of Labour MP Jo Cox in 2016.
The UK Home Secretary has ordered an urgent review of MPs' security, with counter-terror police are leading the investigation and detectives saying they're maintaining an "open mind" about the motive for the attack.