English said the attendance of Princess Astrid would provide an opportunity for Belgium and New Zealand to remember the events which "so profoundly affected" both countries.
The Government will be represented at Tyne Cot by Cabinet minister Nick Smith, and Speaker of the House David Carter will represent Parliament.
In Wellington, commemorations will begin at 3pm on October 12 at the Pukeahu National War Memorial Park.
A memorial gifted to New Zealand by the Belgian Government will be unveiled on the eastern terraces of the park following the ceremony.
Arts Culture and Heritage Minister Maggie Barry described Passchendaele as "one of the greatest disasters in New Zealand history".
"This devastating loss of life remains the highest one-day death toll suffered by New Zealand forces overseas," Barry said.
"During the Third Battle of Ypres, which included Passchendaele, New Zealand lost nearly 2000 men. We will remember them and all who fought in Belgium."
Ceremonies will conclude at sunset at Buttes New British Cemetery in Polygon Wood where 95 Kiwis are buried.
It is also where the New Zealand "Memorial to the Missing" list the names of the 388 Kiwis who died there, but did not have a grave.