On Friday, at the Port of Napier, the Americans will be landing.
A US Army contingent of about 85 troops, medical support staff and military police, will step ashore from the logistics ship HMNZS Canterbury which is due to arrive in port about 8am.
The American troops will be joining about 1400 New Zealand army, navy and air force personnel taking part in Exercise Alarm Halfa - one of the biggest combined forces exercises to be staged across the Hawke's Bay region in more than a decade.
Defence communications advisor Paul Stein said the 10-day exercise had been five months in the planning, and would see troops movements by land, sea and air into the region.
About 35 US Marines were also in the country and they too would be involved in the exercise - spread throughout Kiwi units.