The mayor of Basque city Bilbao told an event to mark 100 days to the start of the 2023 Tour de France on July 1 that he was eager to show off his city to a global audience.

The 21-stage cycling race frequently embarks outside France. It started in nearby San Sebastian in 1992.

This year's race gets underway with three days of racing in the green hills and seaside towns of one of cycling's heartlands.

"Cycling is in our DNA," said Juan Mari Aburto, Mayor of Bilbao in the autonomous Basque region of Spain.

Aburto said the Basque Country was ready to "show the world that we can host an event of this magnitude."

He said the Tour would put Bilbao in the global spotlight.

"We want to show the world that we have become a modern, dynamic and safe city", he said.

Mayor Aburto said he "hopes to attract many tourists in the future" and, in a race where the organisers pay attention to the scenery for an event broadcast in 190 countries, the stages in the Basque country will provide eye-catching backdrops for million of viewers.

At a ceremony to start the 100-day countdown, elected dignitaries from towns along the Basque part of the route welcomed the Paris-based event organisers ASO.

"The Tour de France is the third-most important sporting event on the planet after the Olympic Games and the World Cup," said the regional lawmaker Unai Rementeria Maiz.

"It will be impossible for the first two to come to Bilbao, so we are very proud to host the Tour," said Maiz, also of the Basque nationalist Party.

- Puy de Dome ascent -

The 2023 Tour route for the men's race is laced from the start with terrain that lends itself to attacks.

The opening stage around the port city of Bilbao culminates near one of the world's most iconic buildings, Frank Gehry's ultra-modernist Guggenheim museum.

The route is an invitation for roadside fans to stake out a place on what should be a packed route to cheer on a local rider to win the first coveted overall leader's yellow jersey.

The stage will bring the global TV audience into the historic Basque centre of Guernica, bombed by the fascists during the Spanish civil war, an attack on civilians immortalised by Pablo Picasso's painting of the same name.

A daredevil finale on the 20km descent to the chic coastal resort of San Sebastian around its horseshoe bay is likely to provide the show on stage two.

The second and third stage in the Basque country take the race to the Pyrenees and over the French border to Bayonne.

Once the race returns to France, highlights include a July 14 national holiday visit to volcanic Puy de Dome, where fans will be banned and the cyclists will ascend alone.

The race could be decided on the last Saturday with a ferocious mountainous stage 20 the scene of a showdown with five mountains to cross on the day.