New Zealanders who bravely fought in France during the First World War have been remembered in Wellington today.

The ceremony at the Pukeahu National War Memorial marks 100 years on Thursday since New Zealand ground troops joined in the Battle of the Somme.

Newstalk ZB reporter Georgina Campbell said rain forced the commemorations indoors, making for an intimate ceremony, with just more than 100 people.

Children and grandchildren of those who fought were at the solemn event, she said.

War Memorial advisory council chair David Ledson said by the end of the first day, the British-led forces had lost more than 19,000 men, 600 Kiwis were among them.

"One-hundred years ago last Thursday the New Zealand division had its first encounter with what has been described as the slow-slaughtering process when they rushed their first yards in the first battle of the Somme."

Acting Prime Minister Bill English paid tribute to the soldiers.

He said what awaited them in the trenches can only be described as mind-shattering.

"They encountered changes in warfare they could not have imagined, with the introduction of tanks and chemicals bringing a cruel reality to their nightmares."

The service ended with a prayer for the soldiers who fought, led by Chaplain Hamish Kirk.

"Grant us the grace to pass these memories on to generations that follow, that we might never take freedom for granted."