Polls open in Bhutan elections: AFP

The Himalayan kingdom of Bhutan began voting Tuesday in general elections with parties vowing to tackle serious economic challenges, calling into question its longstanding policy of prioritising "Gross National Happiness" over growth.

Both parties contesting the vote are committed to a constitutionally enshrined philosophy of a government that measures its success by the "happiness and well-being of the people".

Some voters are expected to have trekked for days to cast their ballots in the landlocked mountain nation of about 800,000 people, similar in area to Switzerland.

In the freezing early morning mountain air, only a few voters lined up as polls opened in the capital Thimpu, an AFP reporter said.

Booths will stay open until 5:00 pm (1100 GMT), with results likely to be announced the following day.

Foremost in the minds of many are the struggles facing the kingdom's younger generation, with chronic youth unemployment and a brain drain.

Bhutan's youth unemployment rate stands at 29 percent, according to the World Bank, while economic growth has sputtered along at an average of 1.7 percent over the past five years.

Young citizens searching for better financial and educational opportunities abroad have left in record numbers since the last elections, with Australia as their top destination.

Around 15,000 Bhutanese were issued visas there in the 12 months before last July, according to a local news report -- more than the preceding six years combined and almost two percent of the kingdom's population.

The issue is front and centre for both parties contesting the poll.