New Zealand and Papua New Guinea are two Pacific Islands states with a common history in the fact that New Zealand and the Territory of Papua were colonized by the United Kingdom (while Germany administered German New Guinea). During World War II, New Zealand soldiers fought in the Battle of the Green Islands. In 1949, Australia established a joint administration over both territories called the Territory of Papua and New Guinea. In September 1975, Papua New Guinea obtained independence from Australia. Soon afterwards, New Zealand recognized and established diplomatic relations with Papua New Guinea.