Russia has repeatedly targeted arms factories in Ukraine since it invaded in 2022, forcing the country to look abroad for secure locations to manufacture defence materials.

"We must help our Ukrainian friends in their fight for freedom. They need a safe place to establish production like the one they are setting up here," Danish Industry Minister Morten Bodskov told AFP late on Monday after putting the first symbolic shovel in the ground in the town of Vojens.

Danish officials said they could not confirm if the site -- due to start producing rocket and drone fuel in autumn 2026 -- was the first of its kind, as others may have been constructed secretly for security reasons.

Ukrainian firm Fire Point, which develops drones and missiles for the military, is establishing the site along with the Danish government.

"We need to increase our production, which is impossible in Ukraine," said Fire Ppoint chief executive Vyacheslav Bondarchuk.

"If we have to choose a country, I would say Denmark is the one that welcomes us best."

Bodskov added that Fire Point would bring "new technologies" of its own an area of western Denmark already home to a burgeoning defence industry.

The site is near the Skrydstrup airbase, which hosts F-16 training for Ukrainian pilots and was the target of mysterious drone flights at the end of September -- along with several Danish airports.

The police were unable to determine the drones' origin but Prime Minister Mette Frederiksen pointed the finger at Russia.

In Vojens, some residents were sceptical about the new facility.

"I don't like it, it's too much. We are a small country, we have paid a lot of money to Ukraine," said Marielle, a woman in her forties who did not want to give her family name.

She said she feared the plant would make Denmark the "next target for Russia".

Danish authorities have vowed to keep the area safe.

"No compromises have been made regarding security for production, of course, but also for the local community," insisted Bodskov.