Former New Zealand prime minister David Lange, 63, architect of the nation's anti-nuclear policy that strained relations with the United States, died of complications from kidney failure Aug. 13 at a hospital in Auckland .

Mr. Lange, Labour Party prime minister from 1984 to 1989, defied the United States and other Western allies in 1985 by banning nuclear arms and nuclear-powered ships from the territory and waters of New Zealand. The ban is still in effect.

He also is credited with giving his nation of 4 million its most radical economic overhaul in an attempt to open its markets. Although he was forced from power in 1989, the center-right National Party that took power the next year continued his economic program.

Mr. Lange, the son of a doctor, started his career as a lawyer who championed the rights of the poor. He became a legislator in the northern city of Mangere, near Auckland, in 1977. In 1983, he was elected Labour leader and 16 months later led his party to power. He was 41, the nation's youngest prime minister of the past century.

A Methodist lay preacher, Mr. Lange spurned the trappings of public life by not moving into the official premier's residence. Instead, he rented a small apartment in Wellington while his first wife, Naomi, and their children remained in Auckland.

Known for his down-to-earth wit, Mr. Lange said to retiring U.S. Ambassador H. Monroe Browne, who owned a racehorse named Lacka Reason, "You are the only ambassador in the world to race a horse named after your country's foreign policy."

In a debate with nuclear weapons supporters at Oxford University, his quips included: "Lean forward; I can smell the uranium on your breath."

Yet his leadership left his party in disarray. It took nine years for Labour to regain power after its defeat in 1990, a year after Mr. Lange resigned as prime minister citing ill health.

He fell out with a powerful group of ministers when he called for a pause in the rapid rate of economic reform. And his nuclear ban put him at odds with the Reagan administration.

His government also abolished farm and export subsidies and such privatized state-run enterprises as the railroad, the postal service and telecommunications -- moves that cost thousands of jobs.

After divorcing in the 1990s, Mr. Lange married his former policy adviser, Margaret Pope, with whom he had a daughter.

He suffered ill health through much of his adult life.

In 1983, he had a stomach-stapling operation in an effort to lose weight. He acknowledged alcoholism in 1999, had multiple bypass surgeries for heart disease and in 2002 underwent chemotherapy for a rare plasma disorder.

In 2003, Mr. Lange won a Right Livelihood Award, known as the "alternative Nobel," after reportedly having been nominated for a Nobel Peace Prize. He also was named to the Order of New Zealand, the nation's highest honor, bestowed on just 20 living New Zealanders at any one time.

He is survived by his wife, Margaret, and four children.

David Lange