On Friday he officially opened a sales and marketing hub in Singapore for the kiwifruit marketer.
He joined a delegation of Maori kiwifruit growers for a traditional Maori blessing of the new office and its whakairo/carving.
Kaumatua Pouroto Ngaropo blessed the office and the carving Te Tipuranga by Tauranga-based carver James Tapiata which symbolises the connection to Zespri's roots in the Bay of Plenty region in New Zealand.
As well as being Singapore's 50th anniversary, this year also marks the 50th anniversary of diplomatic relations between our two countries, Mr Key said ahead of the visit.
Singapore imports more than $1 billion worth of New Zealand goods a year and is a major source of investment.
Singapore was a British colony until 1963, when it merged with the Federation of Malaya, Sarawak and Sabah to form Malaysia.
On August 9, 1965, Singapore left Malaysia and became fully independent. The 50th anniversary celebration will be marked by a parade through the city, and other commemorative events.
Mr Key returns to New Zealand on August 10.