AMSTERDAM (AFP) - Amsterdam was preparing on Monday to paint the town orange ahead of the enthronement of king Willem-Alexander, with millions across The Netherlands geared up to say farewell to a much-adored queen after 33 years.

Willem-Alexander, 46, his future queen Maxima, 41, and their three young daughters arrived to cheers from onlookers and press at Amsterdam's Nieuwe Kerk for a final dress rehearsal on Monday.

The 600-year-old church on Tuesday will be the scene of Willem-Alexander's investiture as the first Dutch king in more than 120 years following the abdication of his mother, Queen Beatrix, 75, earlier in the day.

The outgoing queen paid homage to her son, his wife, and her late husband prince Claus in her final address to the nation on prime-time television late Monday.

"Not power, nor personal will, nor hereditary authority, but only the will to serve the community can give substance to a contemporary monarchy," said an emotional Beatrix.

Willem-Alexander is well-prepared for the task ahead of him and will stand above party and group interests, she said.

The day's ceremonies will be attended by those waiting in line for thrones around the world, including Britain's Prince Charles, Spain's Prince Felipe and Japan's Prince Naruhito and his wife Crown Princess Masako, who is on her first trip abroad in nearly seven years.

'Amsterdam is ready'

Some fanatics were preparing to spend the night on Dam Square, a stone's throw away from the royal palace where Beatrix will sign the act of abdication.

"We want to spend the night here because we want a great view of the balcony scene," Ms Reina Reyes, a Venezuelan who has been living in The Netherlands for a decade, told AFP.

"We are big fans of the Dutch royals, and the fact that Maxima is from South America is also special for us," said Ms Reyes, 59, wearing a bright orange outfit and an orange crown inscribed with the name "Maxima".

Her husband Asarubal was wearing a similar outfit with a crown that said "Willem-Alexander", also in orange, the official colour of the Dutch royal house.

Some of the 10,000-strong police contingent to be deployed around the city used bomb-hunter sniffer dogs and inspection mirrors to ensure the safety of the expected 25,000 orange-clad onlookers who will cheer the royals as they appear on the palace balcony.

Municipal workers were doing a final clean-up around a huge stage erected for hundreds of photographers and television cameras wanting to film the balcony scene.

"We will do everything to ensure that people can enjoy the day in a safe way," Amsterdam's mayor Eberhard van der Laan said at a final press conference on Sunday evening.

Authorities on Monday closed off Amsterdam airspace for civilian aircraft for three days and issued strict orders prohibiting the use of drones on Tuesday, with rooftop snipers to monitor the situation.

"The most important places around Amsterdam will continuously be searched throughout Monday night," Dutch army Major Ruud de Jong told AFP.

Amsterdam's population is set to double with at least 800,000 visitors flooding the city's streets and canals which will be decked out in yet more orange.

Pointing to the magnitude of the occasion, Prime Minister Mark Rutte said: "This is a large-scale event in every way and had to be organised in only three months," after Beatrix announced her abdication in January.

"Amsterdam will be the orange capital of the world," Rutte said.

Elsewhere in the city, some 1,000 people took part in final rehearsals for the so-called "Koningsvaart", the water pageant planned for Tuesday night during which the new king and queen will sail on the city's Ij river, greeting adoring crowds along its banks.

Official farewells to Beatrix, who is to become princess again, include a sumptuous gala dinner in her honour held at the city's landmark Rijksmuseum on Monday evening.

Famed for its Dutch masterpieces such as Rembrandt's Night Watch, the museum was closed to visitors in anticipation of the dinner which will include royals and other high-ranking dignitaries.

The guests sat down to the dinner in the museum's Eregalerij (Gallery of Honour), in the shadow of the Night Watch.

Meanwhile, ordinary Dutch citizens are also preparing to get into the swing of things with traditional "Koninginnenacht", or Queens's Night, celebrations planned all over The Netherlands.

In many city centres including The Hague, Rotterdam, Arnhem and elsewhere, live entertainment and dance parties are planned, as well as street parties and concerts in many neighbourhoods.

"The new king is ready, the Dutch are ready and Amsterdam is ready," said mayor Van der Laan.