Prime Minister John Key will welcome the Samoan Prime Minister, Hon Tuilaepa Lupesoliai Sailele Malielegaoi, to New Zealand later this week to mark the 50th Anniversary of the signing of the Treaty of Friendship between the two countries.

"I visited Samoa in August to mark the anniversary, and I am pleased to host Prime Minister Tuilaepa for a return visit during this special milestone year in our relationship," Mr Key says.

"Samoa is the only country in the world with which New Zealand has a formal Treaty of Friendship.

"This special relationship is built on our shared Polynesian history, cultural ties, people-to-people links and regional cooperation, including through the Pacific Islands Forum.

"The treaty was signed shortly after Samoa gained independence from New Zealand in 1962, and it has been at the heart of our relationship ever since," Mr Key says.

"Regular high-level talks are an important part of our relationship, reflecting the closeness between our two countries and providing an opportunity to discuss and progress bilateral issues.

"In addition, Prime Minister Tuilaepa is a long-serving and respected Pacific leader, and I look forward to discussing regional issues of mutual importance," Mr Key says.