New Zealand profile - Leaders
Head of state: Queen Elizabeth II, represented by a governor-general
Prime minister: John Key
John Key, who has been prime minister since the end of 2008, secured a third term in office for his National Party in the elections of September 2014.
His party's 2008 victory ended nine years of Labour-led government, and the 2014 election result showed a swing to conservative parties, with the Labour and Green parties losing ground.
The National Party fell short of a parliamentary majority in the 2008, 2011 and 2014 elections, governing with the support of smaller parties.
In December 2016, Mr Key announced he would be standing down, citing family reasons for the surprise decision.
Born in 1961 and brought up in relative poverty by his Austrian-Jewish immigrant mother after the early death of his father, Mr Key became a currency trader, and earned a substantial personal fortune.
He rose to be head of foreign exchange at Merrill Lynch in Singapore, and served as a member of the Foreign Exchange Committee of the New York Federal Reserve Bank in 1999-2001.
National Party president John Slater encouraged him to enter politics in 2001, and Mr Key was elected to parliament the following year. He was appointed opposition finance spokesman in 2004, and became party leader in 2006 after Don Brash resigned over allegations of election funding irregularities.
New Zealand has a single-chamber parliament, elected for a three-year term. Coalition or minority governments have been the norm since proportional representation replaced the first past the post system after a referendum in 1993.