Norway has begun to bid a final farewell to King Harald V, a modern and unifying figure in a funeral that is being attended by European royals and foreign dignitaries.

The funeral procession is the culmination of 13 days of national mourning since the 89-year-old monarch's death on 28 August.

Ukrainian President Volodymyr Zelenskyy, Britain's Prince William, Spain's royal couple, the presidents of Finland, Germany and the Czech Republic as well as the French and Thai prime ministers are among those in Oslo who will pay their respects.

The casket is being carried on an artillery carriage along the city's main avenue to Oslo's Lutheran cathedral, where the ceremony began with a minute of silence observed across the country.

Norway's royal family, led by new King Haakon VIII, foreign royals, heads of state and dignitaries are taking part in the procession on foot.