Copenhagen Mayor Frank Jensen said on Monday it was in a tough competition with other cities to attract talents from around the world, after the Danish capital city was ranked as the world's best city for attracting talents.

Copenhagen is the best city in the world for attracting, maintaining and developing business talents, according to the Global Talent Competitive Index, released on Monday in Davos.

The index, released by international graduate university Insead, put Copenhagen ahead of Zurich, Helsinki, San Francisco and Gothenburg, Sweden, in its first-ever ranking of global cities.

"We are in tough competition with other cities to attract investment, businesses and talents," Jensen said in a news release.

"I see it as a recognition of the many things we are doing to create an attractive city with high quality of life and good career opportunities," he said.

To be more attractive to talent and businesses, Copenhagen has launched Greater Copenhagen with 79 municipalities and three regions in eastern Denmark and southern Sweden.

By doing so, Copenhagen's population has risen from 600,000 to 4 million people to create a critical mass to compete with other European growth cities such as Stockholm, Hamburg and Amsterdam.

However, the new index, GTCI 2017, saw Denmark drop three spots to eighth from last year's ranking of nations.

Switzerland topped the rankings, followed by Singapore, the United Kingdom, the United States, Sweden, Australia, Luxembourg, Denmark, Finland and Norway.